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3 years ago

A company installs 5000 light bulbs, each with an average life of 500 hours, standard deviation of 100

Mathematics

1 answer:

gulaghasi [49]3 years ago

3 0

Answer:

C. 97.1 should be your answer

Step-by-step explanation:

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Pls help math problem is hard

vazorg [7]

Answer:

Reflect over y axis and go 7 units down.

Step-by-step explanation:

It will match the triangles.

7 0

3 years ago

An art history professor assigns letter grades on a test according to the following scheme.A: Top 5% of scoresB: Scores below th

adoni [48]

Answer:

Grade B score:

$76 \leq x \leq 89$

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 73.3

Standard Deviation, σ = 9.7

We are given that the distribution of score on test is a bell shaped distribution that is a normal distribution.

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

B: Scores below the top 5% and above the bottom 62%

We have to find the value of x such that the probability is 0.62

$P( X > x) = P( z > \displaystyle\frac{x - 73.3}{9.7})=0.62$

$= 1 -P( z \leq \displaystyle\frac{x - 73.3}{9.7})=0.62$

$=P( z \leq \displaystyle\frac{x - 73.3}{9.7})=0.38$

Calculation the value from standard normal z table, we have,

$\displaystyle\frac{x - 73.3}{9.7} = 0.305\\\\x = 76.26$

We have to find the value of x such that the probability is 0.05

$P(X < 0.95) = \\\\P( X < x) = P( z < \displaystyle\frac{x - 73.3}{9.7})=0.95$

Calculation the value from standard normal z table, we have,

$\displaystyle\frac{x - 73.3}{9.7} = 1.645\\\\x = 89.26$

Thus, the numerical value of score to achieve grade B is

$76 \leq x \leq 89$

7 0

3 years ago

3/7 + 1/3 is equivalent to

cestrela7 [59]

Answer:

7/21+9/21=16/21

Hope it helps

Have a good day

8 0

3 years ago

Read 2 more answers

The cost of renovating the den is $4.55 per square foot for the carpet and $1450 for a TV. Write an equation to represent the si

7nadin3 [17]

4.5X+1450=C

X represents the amount of square feet
C represents the total cost

7 0

3 years ago

Read 2 more answers

What is the probability of selecting a seventh-grader from a school that has 250 sixth-graders, 225 seventh-graders, and 275 eig

Nina [5.8K]

Answer:

3/10 or 0.3 or 30%

Step-by-step explanation:

Its 225/750 total students

We simplify this by dividing by 5

45/150

Divide by 5 again

9/30

Divide by 3

3/10

3 0

3 years ago