Question

In an effort to increase sales, a company is considering a new training program for its sales department. An advertisement claims that the training program leads to a mean increase of $5000 in monthly sales. To study the program's effectiveness, the company selects 20 sales representatives, randomly assigning 10 to the training program and 10 to serve as control. On average, the representatives who participated in the training brought in $8231 more in monthly sales than the control, and the 95% confidence interval for the difference in means was (2799, 13663) dollars. Does this confidence interval provide convincing statistical evidence that the mean increase in sales is different from the advertised value?

A) No, because $0 is outside the interval the results are not statistically significant.
B) No, because $5000 is included in the interval the results not statistically significant.
C) Yes, because $0 is outside the interval the results are statistically significant.
D) Yes, because the representatives were randomly assigned and $8231 is different from $5000.
E) Yes, because $8231 is inside the confidence interval the results are accurate.

Answer 1

B) No, because $5000 is included in the interval the results not statistically significant.

Step-by-step explanation:

The confidence interval for the difference in means is (2799, 13663) dollars, which means that we are 95% confident that the true difference in means falls between these two values.

Since the value $5000 falls within this interval, we cannot reject the null hypothesis that the true mean increase in sales is $5000.

In other words, the results are not statistically significant and we cannot conclude that the training program leads to a different mean increase in sales than the advertised value.

Hope this helps!