Question

According to J.D. Power & Associates, the mean purchase of a smart0hone device ( Such as an iphone or Galaxy ) in 2016 was $318. In 2017, a random sample of 20 business managers who owned a smart phone device showed a mean purchase of $341 with a sample standard deviation of $23. (a) at alpha = 0.5, has the mean purchase increased? State the hypotheses of significance and decision rule clearly.

Answer 1