You are starting your new role as a product manager. The Marketing area has a new marketing campaign that they just tested with your product. Marketing analytics sends you a Difference in Means Confidence Interval (new campaign - current campaign) of (-$3.30 , $43.30) at the 2% significance level. Marketing Analytics is already playing politics with you, withholding information and only providing some of the data used to create the confidence interval. Marketing Analytics tells you they collected a number of days of data with the new campaign, finding a sample standard deviation of $45. And they tell you they collected 160 days of data with the current campaign, finding a sample standard deviation of $40.
You need to let Marketing Analytics know they cannot push you around! Rather than asking for more information, you demonstrate your analytics ability by calculating the number of days used for the new campaign.

Requried:
Write the number of days below. Please round to the nearest whole number.