Question

Do you want to own your own candy store? Wow! With some interest in running your own business and a decent credit rating, you can probably get a bank loan on startup costs for franchises such as Candy Express, The Fudge Company, Karmel Corn, and Rocky Mountain Chocolate Factory. Startup costs (in thousands of dollars) for a random sample of candy stores are given below. Assume that the population of xvalues has an approximately normal distribution.

91

177

134

91

75

94

116

100

85

(a) Use a calculator with mean and sample standard deviation keys to find the sample mean startup cost x and sample standard deviation s. (Round your answers to one decimal place.)

x =	____ thousand dollars
s =	____ thousand dollars

(b) Find a 90% confidence interval for the population average startup costs μ for candy store franchises. (Round your answers to one decimal place.)

lower limit	____ thousand dollars
upper limit	____ thousand dollars

Answer 1

(a)

From the given data, the mean and standard deviation are got from calculator as follows:

	107.0 thousand dollars
s	31.5 thousand dollars

(b)

SE = s/

= 31.5199/ = 10.5066

= 0.10

ndf = n - 1= 9 - 1= 8

From Table, critical values of t = 1.8595

Confidence Interval:

107 (1.8595 X 10.5066)

= 107 19.5371

= ( 87,5 ,126.5)

So, Answer is:

lower limit	87.5 thousand dollars
upper limit	126.5 thousand dollars