Question

Armonte and Grayson, of Watch Mi Whip, Watch Mi Quartile! Auto Suppliers, were called in to help assess data on customers that had taken a test drive in the new electric Hoosur Dadi V sports car that had a top speed of 250/mph. Using an σ of 5.5 customers, find

a. The mean of the sample mean and the standard error of the mean when there is a random sample of 81 customers.

b. The mean of the sample mean and the standard error of the mean when there is a random sample of 49 customers.

Answer 1

Solution :

Given that ,

mean = = 250

standard deviation = = 5.5

a

n = 81

sample distribution of sample mean is ,

=

= 250

sampling distribution of standard deviation

=  / n = 5.5/ 81=0.61

= 0.61

b

n = 49

sample distribution of sample mean is ,

=

= 250

sampling distribution of standard deviation

=  / n = 5.5 / 49

= 0.7857=0.79 rounded