Question

Are some cities more windy than others? Does Chicago deserve to be nicknamed "The Windy City"? Given below are the average wind speeds (in miles per hour) for 45 selected cities.

8.7	12.3	8.6	11.5	9.1	8.8	35.1	6.1	7.0
7.2	11.8	10.9	7.6	9.2	9.1	8.1	9.0	8.9
9.2	10.7	10.5	9.6	7.8	11.4	9.5	7.7	8.8
8.8	12.9	8.3	7.8	5.9	10.4	10.4	9.6	8.7
10.1	10.5	7.9	10.6	8.5	8.8	9.4	8.8	9.3

(a)

Calculate

y

and s in mph for the data given. (Round your answers to two decimal places.)

y= ___. mph

s= ____. mph

(b)

Calculate the interval

y ± ks for k = 1.

(Round your answers to two decimal places.)

( 5.66,__)

Count the number of measurements that fall within the interval and compare this result with the number that you would expect according to the empirical rule.

There are 44 measurements that fall in this interval. Based on the empirical rule, we expect 30.6

measurements to fall in this interval. There are more measurements in the interval compared to what is expected from the empirical rule.

Calculate the interval

y ± ks for k = 2.

(Round your answers to two decimal places.)

(1.53, __)

Count the number of measurements that fall within the interval and compare this result with the number that you would expect according to the empirical rule.

There are 44 measurements that fall in this interval. Based on the empirical rule, we expect 42.75

measurements to fall in this interval. There are more measurements in the interval compared to what is expected from the empirical rule.

Calculate the interval

y ± ks for k = 3.

(Round your answers to two decimal places.)

(__,__)

Count the number of measurements that fall within the interval and compare this result with the number that you would expect according to the empirical rule.

There are 44 measurements that fall in this interval. Based on the empirical rule, we expect 44.865

measurements to fall in this interval. There are fewer measurements in the interval compared to what is expected from the empirical rule.

Answer 1

There are 44 measurements that fall in this interval. Based on the empirical rule, we expect (45*0.68=) 30.6

measurements to fall in this interval. There are more measurements in the interval compared to what is expected from the empirical rule.

the interval

y ± ks for k = 3=(-2.62,22.21)

There are 44 measurements that fall in this interval. Based on the empirical rule, we expect (45*0.997=) 44.865

measurements to fall in this interval. There are fewer measurements in the interval compared to what is expected from the empirical rule.