1. (LO 3.1, 3.3, 3.5, 3.6, 3.7) Let’s see how using a visualization can assist with data analysis. We will use a transformed version of the data in the file titled Skydio Drone dataset TRANSFORMED.xlsx. This is a transformed version of the data set used in Problems 6–11. This transformed file splits the first two weeks of data into two groups and lists each individual invoice amount. In the following three steps, assess if the average invoice for Week 1 is significantly different than the average invoice for Week 2.

Complete the following steps:

a. Calculate the mean for both sets of data.

b. Create a bar chart for the two means. Why is a bar chart appropriate for these data?

c. Based on the bar chart, do you think that the differences between the two groups are significantly different?

d. Using the Data Analysis ToolPak, run a t-test assuming unequal variance.

i. Select all of the data for Week 1 in the Variable 1 range and all of the data for Week 2 in the Variable 2 range (including the labels).

ii. Place a checkmark next to Labels.

iii. Set the hypothesized mean difference to 0.

iv. Set the alpha to 0.05.

v. Click OK to run the hypothesis test. The results will display automatically on a new sheet in your workbook.

e. Interpret your results of both the bar chart and the t-tests (comparing the two-sample p-value to the alpha of 0.05).

f. Would your results change if alpha were set to 0.10? Explain.

g. Why do you think it is important not only to visually assess the differences between two data sets (as you did with the bar chart in this problem) but also to run a t-test to assess for statistical significance of the differences?