Friend of mine needs an explanation of this problem.

Juliette [100K]

I think the answer would be 1.8

8 0

2 years ago

A machine that produces ball bearings has initially been set so that the true average diameter of the bearings it produces is .5

lara [203]

Answer:

7.3% of the bearings produced will not be acceptable

Step-by-step explanation:

Problems of normally distributed samples can be 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:

$\mu = 0.499, \sigma = 0.002$

Target value of .500 in. A bearing is acceptable if its diameter is within .004 in. of this target value.

So bearing larger than 0.504 in or smaller than 0.496 in are not acceptable.

Larger than 0.504

1 subtracted by the pvalue of Z when X = 0.504.

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

$Z = \frac{0.504 - 0.494}{0.002}$

$Z = 2.5$

$Z = 2.5$ has a pvalue of 0.9938

1 - 0.9938= 0.0062

Smaller than 0.496

pvalue of Z when X = -1.5

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

$Z = \frac{0.496 - 0.494}{0.002}$

$Z = -1.5$

$Z = -1.5$ has a pvalue of 0.0668

0.0668 + 0.0062 = 0.073

7.3% of the bearings produced will not be acceptable

4 0

3 years ago

Logan ran 13 miles in 3 1/4 hours. What was his average rate?

erma4kov [3.2K]

Answer:

ccccc

Step-by-step explanation:

3 0

2 years ago

Read 2 more answers

Solve for y. 3=7(1-1)<br><br>(it isn't 2)

laiz [17]

Answer:

First off, I can't solve for y, there is no y variable.

Second, 3 = 7 ( 1 - 1 ) is not true because 3 ≠ 0 ( 3 doesn't equal 0 ) :

3 = 7 ( 1 - 1 )

3 = 7 ( 0 ) ( Simplify Parenthesis )

3 = 0 ( Multiply 7 and 0 )

3 ≠ 0

4 0

2 years ago

What do you want to find out? > The rate at which Bill puts shringles on a rood. What do you know? > Bill and Chip each fi

denis23 [38]

Answer:

(a) b = (4/7)c

(b) Bill: 40 shingles/hour; Chip: 70 shingles/hour

Step-by-step explanation:

Let b and c represent Bill's and Chip's rates in shingles per hour, respectively. Then we have ...

7b = 4c

c - b = 30 . . . . shingles per hour difference in rates

(a) Bill's rate in terms of Chip's rate can be found by dividing the first equation by 7

b = (4/7)c . . . . . Bill's rate is 4/7 of Chip's rate

__

(b) To find the rates, we can multiply the second equation by 7 and substitute using the first equation:

7c -7b = 210

7c -4c = 210

c = 210/3 = 70

b = (4/7)(70) = 40

Bill's rate is 40 shingles per hour; Chip's rate is 70 shingles per hour.

3 0

2 years ago