Question

Question 6 (1 point) You own a small storefront retail business and are interested in determining the average amount of money a typical customer spends per visit to your store. You take a random sample over the course of a month for 10 customers and find that the average dollar amount spent per transaction per customer is $83.652 with a standard deviation of $15.2173. Create a 99% confidence interval for the true average spent for all customers per transaction. 1) (-68.013, 99.291 ) 2) (68.013.99.291) 3) (68.402.98.902) 4) (78.84, 88.464) 5) (80.402, 86.902)

Answer 1

Question 6: Correct answer: Option (2) (68.013,99.291)

since

The provided sample mean is X = 83.652 and the sample standard deviation is 8 = 15.2173. The size of the sample is n = 10 and the required confidence level is 99% The number of degrees of freedom are df = 10-1=9, and the significance level is a = 0.01. Based on the provided information, the critical t-value for a = 0.01 and df = 9 degrees of freedom is te = 3.25. The 99% confidence for the population mean u is computed using the following expression C1 = (x ) Therefore, based on the information provided, the 99 % confidence for the population mean u is CI = 83.652 3.25 x 15.2173 10 .83.652 + .05.052 + 10 ) = (83.652 - 15.639,83.652 +15.639) = (68.013, 99.291)

Question 9:

Correct answer: Option (1) (-1.4623, 31.6003)

since

The provided sample mean is X = 15.069 and the sample standard deviation is 8 = 18.4384. The size of the sample is n = 12 and the required confidence level is 99% The number of degrees of freedom are df = 12-1= 11, and the significance level is a = 0.01 Based on the provided information, the critical t-value for a = 0.01 and df = 11 degrees of freedom is te = 3.106. The 99% confidence for the population mean y is computed using the following expression CI = (* * * * * x + kovin) Therefore, based on the information provided, the 99% confidence for the population mean u is CI = ( 15.069 - Geo 3.106 x 18.4384 0 712 3.106 18.4384 12 ) = (15.069 - 16.531, 15.069 +16.531) = (-1.462, 31.6)