The life of light bulbs is distributed normally. The variance of the lifetime is 900 and the mean lifetime of a bulb is 520 hours. Find the probability of a bulb lasting for at most 576 hours. Round your answer to four decimal places.

Answer:

Jacki did not subtract 12 from 8 correctly i believe

here x+3y=13

x=13-3y.....1st equation

-3x+2y=27......2nd euation

now putting the value of x from equation 1st in 2nd we will get

-3(13-3y)+2y=27

-49+9y+2y=27

11y=27+49

y=76÷11

y=6.9

now again putting the value of y in equation 1st we get

x=13-3×6.9

x=13-20.7

x=7.7

Answer:

slope of fig 1st(m)= 1/4

y-intercept of 1st fig=-1

slope of fig 2= -1

y-intercept of 2nd fig=2

Step-by-step explanation:

Answer:

area of triangle is

[tex]\frac{1}{2} * b*h\\\\\frac{1}{2} *6*8\\\\6*4=24[/tex]

Answer:

Step-by-step explanation:

Let width of rectangle =X

So length=5x

Given area of rectangle =320inch

Area of rectangle =length ×width

Length×width=320

5X×X=320

5x^2=320

x^2=320/5

x^2=64

So X=√64

Width x= 8inch

Length 5x=5×8

= 40 inch

Perimeter of rectangle =2(length+width)

=2(40+8)

=2(48)

=96inch

Answer:

I think it's 3

Step-by-step explanation:

If 2 is c than subtract  it and it's 3?

Answer:

The answer is D. II 1 > -2 and III -2< 1 Hopefully this is helpful!

Step-by-step explanation:

Answer:

3375 is the answer.

Step-by-step explanation: 8500- 1025=7475

so 1025 is every to years so we need to subtract 7475-1025-1025-1025-1025 so each 1025 is 2 yrs.

I hope this works :)

Answer:

Step-by-step explanation:

28.50/3=9.50 dollars per hour

y=9.50h

Trina earns $19.00 for 2 hours

Trina earns $42.75 for 4.5 hours

Answer:

If Trina earns $28.50 in 3 hours, that means she earns $9.50 per hour.

9.50h = m   --->  earnings = 9.50 x hours

2 hours = 9.50 ( 2) =  $19

4.5 hours = 9.50 ( 4) = $42.75

Step-by-step explanation:

From the graph, [tex]y=mx+b[/tex] and m < 0 (The slope right here is less than 0.)

That means cut ( b ) and ( d ) choice, they both are wrong.

Now look at ( a ) and ( c ).

For ( a ) It's just f(x) = -2x but the graph that's shown here intercepts y-axis at (0,2).   f(x) = -2x is just slope and intercepts y-axis at (0,0)

So the answer is ( c )

Answer:

197.28 meters in 6 minutes

Step-by-step explanation:

13.7 seconds ÷ 25 meters = 0.548 meters in 1 second

6 minutes = 360 seconds (6 minutes x 60 seconds in every minute = 360 seconds)

0.548 meters in 1 second x 360 seconds = 197.28 meters in 6 minutes

Hopefully this helped! Sorry if wrong. You are loved and you are beautiful/handsome!

-Bee

Answer:

5/1

Step-by-step explanation:

Answer:

????

Step-by-step explanation:

Answer:

The standard deviation increases, it's mean, medium and mode, if you put them in order and then go through and get your middle number it'll be 81.

If a score of 50 is added to the data set,

The standard deviation increases.

The range increases.​

"It is the average of all elements of the data set."

"It is the middle number in a sorted list of numbers."

[tex]SD=\sqrt{\frac{\sum{(x-M)^{2}} }{N} }[/tex]

where, SD is the population standard deviation

N : the size of the population

x : each value from the data

M : the mean of the data

range = maximum value - minimum value

For given situation,

Consider the original set of test scores: 71, 75, 80, 81, 81, 84, 89, 93

N = 8

range R = 93 - 71

⇒ R = 22

Mean M = (71 + 75 + 80 + 81 + 81 + 84 + 89 + 93)/8

⇒ M = 654/8

⇒ M = 81.75

Now, we find the median K

First we sort given data set: 71, 75, 80, 81, 81, 84, 89, 93

The middle numbers are 81 and 81

So, the median is the average of 81, 81

So, K = 81

Now, we calculate the standard deviation.

[tex]SD=\sqrt{\frac{[(71-81.75)^{2}+(75-81.75)^{2}+...+(89-81.75)^{2}+(93-81.75)^{2}] }{8} }[/tex]

⇒ SD = 6.61

Consider, the set of test scores with 50 added to the data set.

N = 9

range R = 93 - 50

⇒ R = 43

Mean M =  (71 + 75 + 80 + 81 + 50 + 81 + 84 + 89 + 93)/9

⇒ M = 704/9

⇒ M = 78.22

Now, we find the median K

First we sort given data set: 50, 71, 75, 80, 81, 81, 84, 89, 93

The middle number is 81.

So, the median is K = 81

Now, we calculate the standard deviation.

[tex]SD=\sqrt{\frac{[(71-81.75)^{2}+(75-81.75)^{2}+...+(50-81.75)^{2}+(93-81.75)^{2}] }{9} }[/tex]

⇒ SD = 11.76

So, we can observe that if a score of 50 is added to the data set, the correct statements are:

The standard deviation increases.

The range increases.​

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Answer:

(1)Hoops shadow would be 6 ft (2) model would be 3 cms

Step-by-step explanation:

9 / 3 = 3   3 x 2 = 6 ft

15 / 5 =3    3 x 1 = 3 cm

Answer:

33 1/3

Step-by-step explanation:

Answer:

35 degrees

Pleaase seek help u need to be smarter than this giv me brainilest

Given:

The equation is

[tex]F=\dfrac{9}{5}C+32[/tex]

To find:

Whether there is a proportional relationship between C and F.

Solution:

If there is a proportional relationship between C and F, then the line of given equation passes through (0,0) and the equation must be true for (0,0).

Put F=0 and C=0 in the given equation.

[tex]0=\dfrac{9}{5}(0)+32[/tex]

[tex]0=0+32[/tex]

[tex]0=32[/tex]

This statement is not true because [tex]0\neq 32[/tex].

It means the line of given equation does not passes through (0,0). So, it s not a proportional relationship.

Hence, there is not a proportional relationship between C and F.

Answer:

korrect

Step-by-step explanation:

it looks right

Answer:

100 people

Step-by-step explanation:

Population Of People=115Percentagencrease=15%

The New Population corresponds to 115%

(That is 100+15)

We want to find the population that corresponds to 100% that is the original population.

Therefore Original Population;

[tex] \frac{100}{115}\times {115}{} [/tex]

[tex]100 \: people[/tex]

It is D

I just took the test and got it right

The biconditional statement is x = 5 if and only if x + 5 = 10.

Option D is the correct answer.

An expression is a way of writing a statement with more than two variables or numbers with operations such as addition, subtraction, multiplication, and division.

Example: 2 + 3x + 4y = 7 is an expression.

We have,

Biconditional statement.

This means,

The statement and its converse are both true.

Now,

x = 5 if and only if x + 5 = 10

This shows that both the statement and its converse are true.

Thus,

x = 5 if and only if x + 5 = 10 is a biconditional statement.

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Answer:

22 times 8 is equal to 176

Step-by-step explanation:

9514 1404 393

Answer:

  $28.40

Step-by-step explanation:

Using the given information, we can write three equations relating the three item prices. Let c, b, and j represent the cost of 1 item each of cake, bread, and juice.

  3c +4b = 18.60

  2c +2j = 12.34

  c = 2b

Multiplying the third equation by 2 gives an expression for 4b that we can substitute into the first equation.

  2c = 4b

  3c +2c = 18.60

  c = 18.60/5 = 3.72

Doubling the second equation almost gives us the purchase we want.

  2(2c +2j) = 2(12.34)

  4c +4j = 24.68

Adding one more cake to this give the desired purchase:

  (4c +4j) +c = 24.68 +3.72

  5c +4j = 28.40

The total cost of 5 pieces of cake and 4 glasses of juice is $28.40.

Answer: A, B, and E

Step-by-step explanation:

The true statements are (A) A could be {1, 2, 3} and (B) A could be {1, 2, 3, 4}, where A  is a subset of S

The sample space is given as:

S = {1, 2, 3, 4, 5, 6, 7, 8}

The possible subsets of S are as follows:

Using the above highlights, the possible set of A are:

Hence, the true statements are (A) and (B)

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Answer:

here

Step-by-step explanation:

Alex is writing statements to prove that the sum of the measures of interior angles of triangle PQR is equal to 180°. ... Triangle PQR has vertex P on line n and vertices Q and R on line m. Angle QPR is 80 degrees. Segment PQ makes 40 degrees angle with line n and segment PR makes 60 degrees angle with line n.

Answer:

Angle PQR measures 40 degrees

Step-by-step explanation:

No explanation took the test got it right.

Little late but, oh well, better late than never.

Answer:

10000010

Step-by-step explanation:

10^7 is 10000000 plus 9 plus 1^3 which is 1.

10000000+9+1=10000010

Answer:

10000010

Step-by-step explanation:

Lets break down this problem. 10^7 is equal to 10000000 because the exponent is 7 so we add 7 zeros at the end of 1. 1^3 is equal to 1 because any 1 to the power of a positive integer is 1. So, the equation becomes 10000000+9+1 which is equal to 10000010.  

Answer:

Step-by-step explanation:

I dont know if you meant to punch in a c into the equation but if you didnt mean to i have both answers

Answer:

3

Step-by-step explanation:

Answer:

3

Step-by-step explanation: