A restaurant wants to test a new in-store marketing scheme in a small number of stores before rolling it out nationwide. The new ad promotes a premium drink that they want to increase the sales of. 18 locations are chosen at random and the number of drinks sold are recorded for 2 months before the new ad campaign and 2 months after. The 90% confidence interval to estimate the true average difference in nationwide sales quantity before the ad campaign and after is (-5.25, 12.87). Which of the following is the appropriate conclusion? The differences were calculated as (after ad campaign - before ad campaign).

Question 6 options:

1)

We are 90% confident that the average difference in sales quantity for all stores is positive, with the higher sales being before the ad campaign.

2)

We are 90% confident that the average difference in sales quantity for all stores is negative, with the higher sales coming after the ad campaign.

3)

There is not a significant difference between the average sales quantity before or after the ad campaign.

4)

We are 90% confident that the average difference in sales quantity for all stores is negative, with the higher sales being before the ad campaign.

5)

We are 90% confident that the average difference in sales quantity for all stores is positive, with the higher sales coming after the ad campaign.