A clothing company produces denim jeans. The jeans are made and sold with either a regular cut or a boot-cut. To estimate the proportion of all customers in Tacoma, WA, who prefer boot-cut jeans, a marketing researcher examined sales receipts for a random sample of 178 customers who purchased jeans from the firm’s Tacoma store. 56 of the customers in the sample purchased boot-cut jeans. Construct the 99% confidence interval to estimate the proportion of all customers in Tacoma, Washington, who prefer boot-cut jeans and interpret the confidence interval (please write the interval boundaries to THREE decimal places

99% confidence interval for the proportion of all customers in Tacoma, Washington, who prefer boot-cut jeans is [0.225 , 0.405].

Step-by-step explanation:

We are given that a marketing researcher examined sales receipts for a random sample of 178 customers who purchased jeans from the firm’s Tacoma store. 56 of the customers in the sample purchased boot-cut jeans.

Firstly, the Pivotal quantity for 99% confidence interval for the population proportion is given by;

                           P.Q. =    ~ N(0,1)

where, = sample proportion of customers who purchased boot-cut jeans = = 0.315

           n = sample of customers = 178

           p = population proportion of customers who prefer boot-cut jeans

Here for constructing 99% confidence interval we have used One-sample z test for proportions.

So, 99% confidence interval for the population proportion, p is ;

P(-2.58 < N(0,1) < 2.58) = 0.99  {As the critical value of z at 0.5% level

                                                 of significance are -2.58 & 2.58}  

P(-2.58 < < 2.58) = 0.99

P( < < ) = 0.99

P( < p < ) = 0.99

99% confidence interval for p = [ , ]

    = [ , ]

    = [0.225 , 0.405]

Therefore, 99% confidence interval for the proportion of all customers in Tacoma, Washington, who prefer boot-cut jeans is [0.225 , 0.405].

The interpretation of the above confidence interval is that we are 99% confident that the proportion of all customers in Tacoma, Washington, who prefer boot-cut jeans will lie between 0.225 and 0.405.

2 1/2 feet

step-by-step explanation: