Question

The accompanying data represent the miles per gallon of a random sample of cars with a three-cylinder, 1.0 liter engine.

(a) compute the z- score corresponding to the individual who obtained 38.1 miles per gallon. Interpret this result

(b) determine the quartiles

(c) compute and interpret the interquartile range, IQR

(d) determine the lower and upper fences. Are there any outliers?

32.5 36.0 37.9 38.7 40.3 42.4

34.1 36.3 38.1 39.0 40.5 42.7

34.5 37.5 38.2 39.1 41.3 43.3

35.8 37.7 38.5 39.6 41.6 48.8

(a) compute the z-score corresponding to the individual who obtained 38.1 miles per gallon. Interpret this result. Determine if the standard deviation is below or above the mean or median. (type integers or decimals rounded to two decimal places as needed.)

The z-score corresponding to the individual is __and indicates that the data value is __ standard deviation(s) __ the __.

(b) determine the quartiles. (Type an integer or a decimal. do not round.)

Q1=

Q2=

Q3=

(c) compute and interpret the interquartile range, IQR. Select the correct choice below and fill in the answer box to complete your choice. (type an integer or a decimal. do not round.)

A. the interquartile range is __ mpg. it is the range of the observations between the lower and upper fences.

B. the interquartile range is __mpg. it is the range of the middle 50% of the observations in the data set.

C. the interquartile range is __mpg. it is the range of all of the observations in the data set.

D. the interquartile range is __mpg. it is the range of the observations between either the lower or upper quartile and the middle quartile; it captures 25% of the observations.

(d) Determine the lower and upper fences. Are there any outliers?

The lower fence is ___. (type an integer or decimal. do not round.)
The upper fence is ___. (type an integer or decimal. do not round.)

Are there any outliers? select the correct choice below and, if necessary, fill in the answer box to complete your choice.

A. the outlier(s) is/are ___. (type an integer or a decimal. do not round. use a comma to separate answers as needed.)

B. There are no outliers.

Answer 1

a) z- score= 38.1 - mean / s.d