Three girls and nine boys sat a Physics examination.
The three girls' marks were 92%, 80% and 71%.
The mean of all 12 marks was 84%.
The standard deviation of all 12 marks was 5%.
Calculate the standard deviation of the boys' marks.

Homer would have taken approximately 8.11 hours to do the job by himself.

Let h be the time it would take Homer to do the job by himself, and let m be the time it would take Mike to do the job by himself. We know from the problem that:

m = h - 1 (Mike can do the job one hour quicker than Homer)

We also know that they worked together for 4 hours, so they completed 4/h + 4/m of the job. We can set up an equation based on this:

4/h + 4/m = 1 (they completed the entire job)

Substituting m = h - 1, we get:

4/h + 4/(h-1) = 1

Multiplying both sides by h(h-1), we get:

4(h-1) + 4h = h(h-1)

Simplifying:

8h - 4 =

[tex]h^2 - h[/tex]

Rearranging:

[tex]h^2 - 9h + 4 = 0[/tex]

Using the quadratic formula, we get:

[tex]h = (9 ± \sqrt{(9^2 - 414)) / 2} [/tex]

Since we are looking for a positive value of h, we take the positive square root:

h ≈ 8.11

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The sum of 10 3/4 and 12 1/4 is 23.

To add the mixed numbers 10 3/4 and 12 1/4, follow these steps:

Step 1: Add the whole number of parts.

Add the whole numbers 10 and 12 to get:

10 + 12 = 22

Step 2: Add the fractional parts separately.

Add the fractions 3/4 and 1/4 separately. To do this, find a common denominator, which in this case is 4. Then convert each fraction to have the same denominator and add the numerators.

For 10 3/4, the fraction 3/4 has the same denominator, so we keep it as is.

For 12 1/4, the fraction 1/4 also has the same denominator, so we keep it as is.

Then we add the numerators of the fractions:

3/4 + 1/4 = 4/4 = 1

Step 3: Add the results from Step 1 and Step 2.

Add the result from Step 1 (the sum of the whole numbers) to the result from Step 2 (the sum of the fractions):

22 + 1 = 23

Therefore, the sum of 10 3/4 and 12 1/4 is 23.

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A sample size of 11 would give a standard deviation of 10 pounds for the Florida Manatees

An equation is an expression that shows how two numbers and variables are related using mathematical operations such as addition, subtraction, exponent, division and multiplication.

The standard deviation of a sample is:

[tex]\sigma_n=\frac{\sigma}{\sqrt{n} } \\\\Where\ n\ is\ sample\ size,\sigma\ is\ standard\ deviation\ and\ \sigma_n\ is\ standard\ deviation\ of\ sample[/tex]

Given that:

[tex]\sigma_n=10,\sigma=33,hence:\\\\10=\frac{33}{\sqrt{n} } \\\\n=10.89[/tex]

A sample size of 11 would give a standard deviation of 10 pounds

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Julie Spiros's basic premium is [tex]740[/tex] per year, and her premium is [tex]1,067.20[/tex] per year.

The basic price factor is multiplied by the regular premium to determine the basic premium. The converted loss is computed by dividing the losses suffered by the loss conversion factor. Due to the basic premium component, the basic premium is lower than the standard premium.

By dividing the amount insured by sum assured, the insurance rate is determined. This indicates that your monthly price would be 10% if you had an insurance coverage of Rs. 10,000 and an adequate amounts of Rs. One of the most important steps in the insurance buying process is figuring out the insurance premium rate.

annual base premium = (vehicle factor) x (driver-rating factor) x (base rate)

[tex]= 1 * 1.85 * 400[/tex]

[tex]= 740[/tex]

Property damage coverage [tex]\frac{25000}{1000}*0.8=20[/tex]

Bodily injury coverage [tex]\frac{50}{100}*2*300=300[/tex]

Comprehensive coverage [tex]\frac{50}{1000}*0.6*12=3.60[/tex]

Collision coverage [tex]\frac{50}{1000}*0.6*12=3.60[/tex]

Adding these costs to the annual base premium, we get:

annual premium = annual base premium + property damage + bodily injury + comprehensive + collision

[tex]= 740 + 20 + 300 + 3.60 + 3.60[/tex]

[tex]= 1,067.20[/tex]

Therefore, Julie's annual premium is [tex]1067.20[/tex]

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Answer

Choice C: (1 1/4 + 2 3/8) / 3/4

Step-by-step explanation:

His salad consists of 1 1/4 cups of purple cabbage and 2 3/8 cups of lettuce. First, you would add those two together to get how much the salad is. THEN divide by how much he eats each day which is 3/4.

Two boxes containing candies were placed on a table, labelled B1 and B2. Box B1 contained 0.0125d of candies while Box B2 contained 0.014d. Therefore, Box B2 contained a greater amount of candies than Box B1, but only by a small amount.

The question asks about two boxes containing candies placed on a table. The boxes are labelled B1 and B2. To answer this question, we must first consider what is contained in each box. Box B1 contains 0.0125d of candies while Box B2 contains 0.014d. Therefore, Box B2 contains a greater amount of candies than Box B1.
It is important to note that the difference between the two boxes is minimal, with Box B2 containing only 0.0015d more candies than Box B1. Thus, both boxes contain similar amounts of candies.

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Yes, Pairing arrangements are possible.

[tex]$\frac{n!}{2^n (n/2)!}$[/tex]

If there are n cysteines, then there are n sulfur atoms that can form disulfide bonds. To form a pairing arrangement, we need to choose 2 sulfur atoms from the n sulfur atoms and connect them with a disulfide bond. We repeat this process until all sulfur atoms are paired up.

The number of ways to choose 2 sulfur atoms from n sulfur atoms is given by the binomial coefficient

[tex]$\binom{n}{2}$[/tex]

Once two sulfur atoms are paired up, we can remove them from the pool of sulfur atoms and continue pairing the remaining sulfur atoms in the same way.

Therefore, the total number of pairing arrangements is given by:

[tex]$\binom{n}{2} \cdot \binom{n-2}{2} \cdot \binom{n-4}{2} \cdots \binom{4}{2} \cdot \binom{2}{2}$[/tex]

which can be simplified as:

[tex]$\frac{n!}{2^n (n/2)!}$[/tex]

Since we are choosing pairs, we divide by 2 for each pair and the order of the pairs doesn't matter. Also, we divide by (n/2)! to account for the fact that the pairs can be arranged in any order.

Note- that n must be even for this formula to hold.

Therefore, the general formula for the number of different pairing arrangements when there are n cysteines (and n is even) is:

[tex]$\frac{n!}{2^n (n/2)!}$[/tex]

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Answer:

Obtuse

Step-by-step explanation:

In general speaking of your options

Straight angles equal exactly 180

Acute angles equal anything less than 90

Obtuse equals anything above 91

Right angles equal exactly 90

Answer:  Nate have 278 cookies now.

Step-by-step explanation:

the original amount of cookies for Nate is 300, and he dropped 145, which means we need to subtract 145 from 300.  And his mom brought him 123 more, which means we need to add 123.

300 - 145 + 123 = 278

Answer:

Multiplying the first equation by 3 and the second equation by 9, we get:

-27y + 12x - 33 = 0

-27y + 90x + 279 = 0

Now, we can subtract the first equation from the second to eliminate y:

-27y + 90x + 279 - (-27y + 12x - 33) = 0

78x + 312 = 0

78x = -312

x = -4

Substituting x = -4 into the first equation, we get:

-9y + 4(-4) - 11 = 0

-9y - 27 = 0

y = -3

Therefore, the solution to the system of equations is (x, y) = (-4, -3).

After using trig identities for all three given functions are a). [tex]x(t) = √29cos(4t - 111.8°)[/tex] , b). [tex]x(t) = √29cos(4t - 68.2°),[/tex] c). [tex]x(t) = e^-2t(√29cos(4t - 111.8°))[/tex].

Using the trig identity [tex]cos(A - B) = cos(A)cos(B) + sin(A)sin(B)[/tex], we can rewrite [tex]x(t) = -2cos(4t) + 5sin(4t)[/tex] using only one cosine function as follows : [tex]x(t) = Rcos(4t - α)[/tex] where [tex]R = √((-2)^2 + 5^2) = √29[/tex] and [tex]α = tan^-1(5/-2) = 111.8°[/tex]. Therefore, x(t) = √29cos(4t - 111.8°)

Similarly, using the same trig identity, we can rewrite [tex]x(t) = 2cos(4t) + 5sin(4t)[/tex] using only one cosine function as follows : [tex]x(t) = Rcos(4t - α)[/tex] where [tex]R = √(2^2 + 5^2) = √29[/tex] and [tex]α = tan^-1(5/2)[/tex] = 68.2°. Therefore, [tex]x(t) = √29cos(4t - 68.2°)[/tex].

Using the same trignometric identity, we can rewrite[tex]x(t) = e^-2t(-2cos(4t) + 5sin(4t))[/tex] using only one cosine function as follows: [tex]x(t) = e^-2t(Rcos(4t - α))[/tex] where R = [tex]√((-2)^2 + 5^2) = √29[/tex] and [tex]α = tan^-1(5/-2) = 111.8°[/tex]. Therefore, x(t) =[tex]e^-2t(√29cos(4t - 111.8°))[/tex]

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Therefore , the solution of the given problem of expressions comes out to be a) 10⁻4.10⁻⁶ = 10⁻¹⁰ , b) -5⁸/-5⁴ = -5⁴ and c) y⁶/y⁷ = 1/y.

Calculations that involve joining, random subdivision variable changing multipliers, and removal are required. They could accomplish the following if they united: An algorithm, some information, and a mathematical challenge. Formulas, factors, and arithmetic operations like additions, deductions, errors, and groupings are all present in a declaration of truth. Words and phrases can be evaluated and analysed.

Here,

a) 10⁻4.10⁻⁶

b) -5⁸/-5⁴

c) y⁶/y⁷

and

To simplify this expression :

a) 10⁻4.10⁻⁶ = 10⁻¹⁰

b) -5⁸/-5⁴ = -5⁴

c) y⁶/y⁷ = 1/y

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Answer:

The model train can travel 2 feet per second.

According to the information in the graph Carissa used the motor for the first twelve minutes, then rowed for the next 12 minutes. During the next 48 minutes she dropped the ship's anchor and finally, during the last 18 minutes she returned to the starting point using the motor.

To identify the moments in which Carissa used the motor, the oars or the anchor we must look at the graph. Additionally, we must be clear that when she uses the motor she is faster than when she uses the oar and that when she uses the anchor she is totally stopped.

Based on the above, we can infer that:

the first twelve minutes, then rowed for the next twelve minutes. During the next forty-eight minutes he dropped the ship's anchor and finally, during the last eighteen minutes, he returned to the starting point using the motor.

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The surface area of the mentioned rectangular prism is calculated to be 168 yd².

The surface area of ​​a three-dimensional object is the total area of ​​all its faces. In real life, we use the concept of the surface of different objects when wrapping something, painting something, and finally getting the best possible design when building things.

Area of rectangle 1

= 6 × 2

= 12 yd²

Area of rectangle 2

= 9 × 2

= 18 yd²

Area of rectangle 3

= 9 × 6

= 54 yd²

Since the prism is made of 2 faces of each type of rectangle and the area of prism is the sum of area of each face:

Area of prism = (12 × 2) + (18 × 2) + (54 × 2)

Area of prism = 24 + 36 + 108

Area of prism = 168 yd²

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Answer: 3690

Step-by-step explanation: i think

The total amount in the account after 5 years is $3690.

Simple interest is the borrowing amount added only to the principal amount.

The Formula to calculate the simple interest is;

                                                 S.I. = P x T x R / 100,

Where S.I. is simple interest, P is the principal amount, T is the time period and R is the interest rate in a year.

In this case, the principal is $3600, the rate is 0.5% (or 0.005 as a decimal), and the time is 5 years.

Plugging these values into the formula, we get:

Interest = $3600 x 0.005 x 5 = $90

So after 5 years, the interest earned on the account is $90. To find the total amount in the account, we need to add the interest to the principal:

Total amount = Principal + Interest = $3600 + $90 = $3690

Therefore, the total amount in the account after 5 years is $3690.

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Answer:

x = 3 cm

Step-by-step explanation:

This is a right-angled triangle where:

hyp = Hypotenuse = 5 cm

adj = Adjacent = 4 cm

opp = Opposite = [tex]x[/tex] cm

To determine the Length of any of the three sides of a right-angled triangle mentioned above, applying the Pythagorean Theorem:

[tex]hyp^{2} = opp^{2} + adj^{2}[/tex]

[tex]5^{2} = x^{2} + 4^{2}[/tex]

[tex]25 = x^{2} + 16[/tex]

[tex]x^{2} = 25 - 16[/tex]

[tex]x^{2} = 9[/tex]

[tex]\sqrt{x^{2}} = \sqrt{9}[/tex]

[tex]x = 3[/tex] cm

The expression which could be used to determine the area of the triangle is: One-half (2) (three-fourths) (StartFraction 7 Over 8 EndFraction).

Expression in math is a combination of numbers, operations, variables, and/or other mathematical symbols that represent a quantity or an action. It is a statement that can be evaluated to a single value, or a set of values. Expressions in math can be used to solve equations, calculate values, and form models of real-world scenarios.

This expression multiplies together the base, two and three-fourths, and the height, StartFraction 7 Over 8 EndFraction, and then divides the result by two to give the area of the triangle.

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The algebra Property used to get  Equation B from Equation A is:

Rewrite one side (or both) using the distributive property​

The 2 equations given are:

A. 5 = -2(x - 1)

B. 5 = -2x + 2

Some of the popular properties of algebra are:

Commutative Property: This states that the numbers on which we operate can be moved or swapped from their position without making any difference to the answer. For example: a + b = b + a , a b = b a

Associative Property: This is defined as when more than two numbers are added or multiplied, the result remains the same, irrespective of how they are grouped. For example: a + ( b + c ) = ( a + b ) + c , a ( b c ) = ( a b ) c

Distributive Property: This is defined as multiplying the sum of two or more addends by a number produces the same result as when each addend is multiplied individually by the number and the products are added together. For example, a(b + c) = ab + bc

Equation A is given as 5 = -2(x - 1)

To get equation B, we rewrite one side (or both) using distributive property

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Complete question is:

A. 5=-2(x-1)

B. 5=-2x+2

How can we get equation B from equation A?

A. rewrite one side (or both) by combining like terms

B. rewrite one side (or both) using distributive property

C. multiply or divide both sides by the same non zero constant.

D. multiply or divide both sides by the same variable expression.

There are 5 ways we can represent the number of dots shown.

What is the combination?

A combination is a choice of items from a group of different items where the order of the choices is irrelevant. either the process of combining or the condition of combining. a combination of several things a synthesis of concepts. something created through fusion: A chord is made up of several notes.

Here, we have

Given: Dots shown and we have to find the ways can you represent the number of dots shown.

We apply here combination and we get

⁵C₁ = 5!/4!

= 5

Hence, there are 5 ways we can represent the number of

dots shown.

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The side length of the square is 1/2 - 1/4(x - 7)^2

To find the side length of the square, we need to first express the perimeter in terms of the side length.

Let s be the side length of the square.

Since a square has four equal sides, the perimeter of the square is given by:

y = 4s

Now, we can express s in terms of y:

s = y/4

Substituting this into the given expression for y:

y = 2 - (x - 7)^2

We get:

s = [2 - (x - 7)^2]/4

Simplifying this equation:

s = 1/2 - 1/4(x - 7)^2

Hence, the side length expression is 1/2 - 1/4(x - 7)^2

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Complete question

The perimeter (y) of a square is y =2 - (x - 7)^2. What’s the side length of the square?

The least amount of money Sally still needs to save before she can buy the iPhone is $125 and the inequality that represents this situation is m ≥ $125

Let "m" be the amount of money Sally still needs to save to buy the iPhone.

The total cost of the iPhone is $200, and Sally has already saved $75. Therefore, the amount of money she still needs to save is:

m = $200 - $75

m = $125

So Sally still needs to save at least $125 before she can buy the iPhone.

Therefore, the inequality that represents this situation is

m ≥ $125

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The option (B) is the correct answer.

Given equation is \[ h=14.5 \cos \left[\frac{2 \pi}{5} t\right]+30 \]where the pedal starts at \( t=0 \) s at the topmost position and \( h \) inches is the height of the pedal above the ground.Now, we are asked to find the time when the pedal reaches a height of 34.48 inches for the second time.In order to find that, we can solve the equation as follows:\[34.48-30=14.5\cos\left[\frac{2\pi}{5}t\right]\]\[\cos\left[\frac{2\pi}{5}t\right]=\frac{4.48}{14.5}\]\[\cos^{-1}\left(\frac{4.48}{14.5}\right)=\frac{2\pi}{5}t\]\[t=\frac{5\cos^{-1}\left(\frac{4.48}{14.5}\right)}{2\pi}\]This gives us,\[t \approx 1.6 \text{ or } 3.7\]The pedal reaches the given height for the second time when \( t = 3.7\) seconds. Therefore, option (B) is the correct answer.

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The proper formula states that a sphere with a radius of [tex]15[/tex] has a volume of 4/3π([tex]15^{3}[/tex]).

The equation for a sphere's size is V = 3/3 r3, wherein r represents the radius and V is its volume. 1⁄2 of an object's circumference makes up its radius. Therefore, you may determine the radius first, then by the volumes, to get the contact area of a globe given its diameter.

Both a circle as well as a sphere are round, if you compare them. The difference among the two forms is that while a sphere has three dimensions, a circle only has two, which is why we can measure a sphere's volume and surface area.

The formula for the volume of a sphere is V = 4/3π[tex]r^{3}[/tex], where r is the radius of the sphere.

Substituting [tex]r=15[/tex], we get

V = 4/3π([tex]15^{3}[/tex])

Therefore, the expression 4/3π([tex]15^{3}[/tex]) gives the volume of a sphere with radius [tex]15[/tex].

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The value of the range of function is found as f(5) = -21.

The range of values that we are permitted to enter into our function is known as the domain of a function.

The given function:

f(x) = {3x-5;x<5

        {-x^2 +4;x>= 5

f(5) = -x^2 +4

Put x = 5

f(5) = -(5)^2 +4

f(5) = -25 +4

f(5) = -21

Thus, the value of the range of the function is found as f(5) = -21.

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Answer:

If x > 5, then y = 2x.

Step-by-step explanation:

If x > 5, then both expressions inside the absolute values are positive, so we can simplify the expression:

y = |x - 5| + |x + 5|

Since x > 5, we know that x - 5 > 0 and x + 5 > 0. Therefore, we can write:

y = (x - 5) + (x + 5)

Simplifying this expression, we get:

y = 2x

So, if x > 5, then y = 2x.

Hope this helped! Sorry if it's wrong. If you need more help, ask me! :]

Accοrding tο the given infοrmatiοn, nοne οf the given vectοrs οr pairs οf vectοrs fοrm a basis fοr R2.

A vectοr space is a cοllectiοn οf οbjects called vectοrs, which can be added tοgether and multiplied by scalars (usually real numbers), in a way that satisfies certain axiοms. These axiοms define the prοperties that the additiοn and scalar multiplicatiοn οperatiοns must have in οrder fοr the set οf vectοrs tο be a vectοr space.

Tο determine if a set οf vectοrs fοrms a basis fοr a vectοr space, we need tο check if the vectοrs are linearly independent and if they span the entire space.

Let's cοnsider the given set οf vectοrs:

v1 = (1, -1)

v2 = (2, -2)

v3 = (3, -2, 0)

v4 = (1, 4, 1)

v5 = (1, -1)

Nοte that these vectοrs have different dimensiοns, sο they cannοt fοrm a basis fοr the same vectοr space.

Vectοrs v1 and v2 are in R2, and they are linearly dependent, since v2 is a scalar multiple οf v1. Therefοre, {v1, v2} cannοt fοrm a basis fοr R2.

Vectοr v3 is in R3, and it is nοt pοssible fοr it tο fοrm a basis fοr R2.

Vectοr v4 is in R3, and it cannοt fοrm a basis fοr R2 either.

Vectοrs v1 and v5 are in R2, and they are alsο linearly dependent, since v5 is a scalar multiple οf v1. Therefοre, {v1, v5} cannοt fοrm a basis fοr R2.

In cοnclusiοn, nοne οf the given vectοrs οr pairs οf vectοrs fοrm a basis fοr R2.

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Complete question:

Answer:

The probability is 4/52

What is Probability?

the extent to which something is probable; the likelihood of something happening or being the case.

"the rain will make the probability of their arrival even greater"

Similar:

likelihood

likeliness

prospect

expectation

chance

chances

odds

possibility

a probable or the most probable event.

plural noun: probabilities

"for a time revolution was a strong probability"

Similar:

probable event

prospect

possibility

good/fair/reasonable bet

the extent to which an event is likely to occur, measured by the ratio of the favorable cases to the whole number of cases possible.

"the area under the curve represents probability"

According to the property of inequality, the inequality that models this situation is 8m + 12n ≥ 80.

What is inequality?

An inequality is a mathematical statement that compares two values or expressions and indicates whether they are equal or not, or which one is greater or smaller.

Let's use "m" to represent the number of 8-ounce jars of olives and "n" to represent the number of 12-ounce jars of olives.

The total amount of olives can be found by multiplying the number of 8-ounce jars by 8 and the number of 12-ounce jars by 12, and then adding them together:

total amount of olives = 8m + 12n

The problem tells us that the total amount of olives is at least 80 ounces. We can represent this information as an inequality:

8m + 12n ≥ 80

Therefore, the inequality that models this situation is 8m + 12n ≥ 80.

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The autograph of the professional basketball player's was worth $250.00 a year ago.

Given that, in the last year, the value of a professional basketball player's autograph rose 40% and it is now worth $350.00.

To determine it worth a year ago, let's call the original value of the autograph "x".

We know that the value increased by 40%, which means it became:

100% + 40% = 140% of its original value.

We can set up the following equation:

140% × x = 350

(140/100)x = 350

1.4x = 350

To solve for x, we can divide both sides by 1.4:

x = 350 ÷ 1.4

x = 250

Therefore, the autograph was worth $250.00 a year ago.

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