Question

How much does a sleeping bag cost? Let's say you want a sleeping bag that should keep you warm in temperatures from 20°F to 45°F. A random sample of prices ($) for sleeping bags in this temperature range is given below. Assume that the population of x values has an approximately normal distribution.

105 120 105 105 75 70 30 23 100 110

105 95 105 60 110 120 95 90 60 70

(a) Use a calculator with mean and sample standard deviation keys to find the sample mean price x and sample standard deviation s. (Round your answers to two decimal places.)

x = $

s = $

(b) Using the given data as representative of the population of prices of all summer sleeping bags, find a 90% confidence interval for the mean price μ of all summer sleeping bags. (Round your answers to two decimal places.)

lower limit $   

Incorrect: Your answer is incorrect.

upper limit $   

Incorrect: Your answer is incorrect.

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 x values has an approximately normal distribution.

92 178 128 97 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

How much does a sleeping bag cost? Let's say you want a sleeping bag that should keep you warm in temperatures from 20°F to 45°F. A random sample of prices ($) for sleeping bags in this temperature range is given below. Assume that the population of x values has an approximately normal distribution. 105 120 105 105 75 70 30 23 100 110 105 95 105 60 110 120 9590 60 70 (a) Use a calculator with mean and sample standard deviation keys to find the sample mean price x and sample standard deviation s. (Round your answers to two decimal places.) (b) Using the given data as representative of the population of prices of all summer sleeping bags, find a 90% confidence interval for the mean price u of all summer sleeping bags. (Round your answers to two decimal places.) lower limit 65.18 upper limit 12x Need Help? 9. - 1 points BBUnderstat12 7.2016. My Notes Ask Your Teacher 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 x values has an approximately normal distribution. 92 178 128 97 75 96 116 10055 (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.) thousand dollars thousand dollars (b) Find a 90% confidence interval for the population average startup costs for candy store franchises. (Round your answers to one decimal place.) lower limit thousand dollars upper limit thousand dollars Need Help? Red

Answer 1

from the given data. mean ž - 4x 1753 87.65 η 20 standard deviations & (xox) n-1 [105-18965) tann 60-87.65) 20-1 14678.55 = √772-5553 27079 S (6) 90% Confidence interval for mean M. is Mttta 90l &- value is 1.729 27.79 87.65+ (1-729) ** 20. 90% confidence interval = 76.91, 98-39

a) from mean given data. i = $x 92+128-1128+ ... 85 = 965 = 107.2 Standard deviation & &(2.7) n-) (92-107-2)(178-107-2).. (85-107-2) 9-1 = 761 3:56 - 1951.695 7613.56 S = 30.8 90% confidence interval for mean is x I critical value *slin e 107.2 I critical blue x 30-8 qo) Critical vale at Afan-1=8 is 1.860 107.2 + 1086 * 3018 -) 107.2 + (19.096) 90% confidence 9okwal > 88.1, 126.3]