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NikAS [45]
3 years ago
11

The life span of a battery is the amount of time the battery will last. The distribution of life span for a certain type of batt

ery is approximately normal with mean 2.5 hours and standard deviation 0.25 hour. Suppose one battery will be selected at random. Which of the following is closest to the probability that the selected battery will have a life span of at most 2.1 hours?
a. 0.055
b. 0.110
c. 0.445
d. 0.890
e. 0.945
Mathematics
1 answer:
Andrew [12]3 years ago
5 0

Answer:

a. 0.055

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean \mu and standard deviation \sigma, the zscore of a measure X is given by:

Z = \frac{X - \mu}{\sigma}

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

\mu = 2.5, \sigma = 0.25

Which of the following is closest to the probability that the selected battery will have a life span of at most 2.1 hours?

This is the pvalue of Z when X = 2.1.

Z = \frac{X - \mu}{\sigma}

Z = \frac{2.1 - 2.5}{0.25}

Z = -1.6

Z = -1.6 has a pvalue of 0.055.

So the correct answer is:

a. 0.055

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guapka [62]

Answer:

1. 795, 23

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Step-by-step explanation:

1. your equation: y = 35x + 235

plug in 16 to find how many pictures she will have on may 16: y = 35(16) + 235

you get y = 795

for the second part, you know are trying to find how long it will take to get to 1024 pictures, so you know your y, but you don't know your x

your equation: 1024 = 35x + 235

solve to get x = 22.54

this rounds up to 23, so your answer is 23

2. multiply 8 times 4 to get 32

subtract 32 from 82 to fin how many she has left

you get 50

for the second part, divide 82 by 4 to find how many day it will take to finish her candy

you get 20.5

so no, she will not have candy to share with her cousins, and she will finish her candy on November 21

3. for this, you have a negative y intercept since you need to make $24 to start profiting

your equation: y = 6x - 24

plug in 50 to x: y = 6(50) - 24

you get y = 276

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for the second part, plug in 400 to y: 400 = 6x - 24

solve to get x = 70.66

this rounds up to 71, so your answer is 71

3 0
3 years ago
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Answer:

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Step-by-step explanation:

36/12= 3

You multiply both numbers by 3:

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Step-by-step explanation:

1,30,2,15,3,10,5,6

That is about it I think

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IrinaVladis [17]

Answer:

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Step-by-step explanation:

To find the number of plants in each row between 5 and 12 requires us to find the factors of the total 28.

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