The shape of the distribution of the time required to get an oil change at a 20-minute oil-change facility is unknown However, records indicate that the mean time is 21.7 minutes, and the standard deviation is 4.8 minutes.

(a) To compute probabilities regarding the sample mean using the normal model, what size sample would be required?

A. The normal model cannot be used if the shape of the distribution is unknown

B. The sample size needs to be less than or equal to 30.

C. The sample size needs to be greater than or equal to 30.

D. Any sample size could be used.

(b) What is the probability that a random sample of n 35 oil changes results in a sample mean time less than 20 minutes? The probability is approximately (Round to four decimal places as needed.)

(c) Suppose the manager agrees to pay each employee a $50 bonus if they meet a certain goal. On a typical Saturday, the oil-change facility will perform 35 oil changes between 10 A. M. and 12 P. M. Treating this as a random sample, there would be a 10% chance of the mean oil-change time being at or below what value?

i am thinking c. sorry if im wrong .

step-by-step explanation:

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step-by-step explanation:

7.   there are 10 data points in the set.   the middle point is between 5 and 6.   the middle point in the top half is 8   and the middle point in the bottom half is 3. to find the iqr , take point 8 and subtract point 3

mid term   point 8 = 100   point 3 = 88

iqr = 100-88 = 12

final   point 8 = 93   point 3 = 78

iqr = 93 - 78 = 15

the final has the greatest iqr

6.   b - there is a high data value that causes the data set to be asymmetrical for the males: the data for males are high and asymmetrical .   there is an outlier for the males that skews the data

5.   the   iqr is a better measure of spread for the movies and basketball games.   since the basketball game has an outlier, we do not want to use standard deviation for measurement.  

3.   the exam median is much higher than the class median.   the median line is farther to the right on the exams

2.   there is no way to tell what the means are from the box and whisker plots.  

the answer is thin because within context, the stanza concludes the and frail tone the people have toward each other, and the fact that it would be thin, makes the most sense compared to "pliable" or "not hard or firm to the touch". hope this , good luck.

step-by-step explanation:

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