Suppose that Randy is an analyst for the bicyling industry and wants to estimate
ID: 3062893 • Letter: S
Question
Suppose that Randy is an analyst for the bicyling industry and wants to estimate the asking price of used entry-level road bikes advertised online in the southeastern part of the United States. He obtains a random sample of n = 1 1 online advertisements of entry-level road bikes. He determines that the mean price for these l l bikes is x = S70375 and that the sample standard deviation is s $189.56. He uses this information to construct a 95% confidence interval for , the mean price of a used road bike. What is the lower limit of this confidence interval? Please give your answer to the nearest cent.Explanation / Answer
Solution:
n = 11
x = 703.75
s = 189.56
df = n-1 = 11 - 1 = 10
t = 2.228 (by using table)
95% confidence interval = x +/- t * s/sqrt(n)
= 703.75 +/- 2.228* 189.56/sqrt(11)
= ( 576.41 , 831.09 )
Lower limit of the confidence interval = $ 576.41
Upper limit of the confidence interval = $ 831.09