Question

Do consumers spend more on a trip to Target or​ Walmart? Suppose researchers interested in this question collected a systematic sample for 84 Target customers and 80 Walmart customers by asking customers for their purchase amount as they left the store. Using the given summary​ statistics, researchers calculated a​ 95% confidence interval for the mean difference between Target and Walmart purchase amounts. The interval was ​($negative 15.05​,$negative 2.95​). Explain in context what this interval means.

Answer 1

Answer:

Step-by-step explanation:

Confidence interval for the difference between two population means is written in the form,

difference in sample means ± margin of error

The difference in sample means is the point estimate for the difference in population means. In the given scenario, the point estimate is the difference in mean amount spent by the sampled customers on a trip to Target or​ Walmart.

Since the interval was (- $15.05​,$2.95), it means that the lower limit is - $15.05 and the upper limit us $2.95.

Therefore, the 95% confidence interval is providing a range that we are 95% confident that the true difference in mean amount spent by Target customers and Walmart customers falls between - $15.05​ and $2.95