1. The electricity consumption of different coolers of same rating were recorded. The following table shows this data:

Power consumption in one hour (number of units of electricity)

0.52 0·75 1·05 2·01 0.79
0·67 0·98 1.51 1·25 1·80
0.49 0.79 0·99 1·11 1·54
0.85 0.95 1·21 1·31 1.41

Perform the following tasks for the data given above:

Enter the data in a spreadsheet and create a frequency distribution. You must create suitable ranges for this distribution. Also you must use array formula for finding this distribution.

Draw the histogram of the data.

Find the relative frequency distribution for the frequency distribution obtained in part

Find the mean and standard deviation of the data using spreadsheet formula.

2. A group of 10 students were given a course on English grammar and spellings. The following table shows their marks in two equivalent tests, one conducted before the course and the other conducted after the course

Marks out of 100

Before the Course 25 75 45 65 35 80 50 66 71 20
After the Course 40 76 50 63 38 81 70 71 70 50

Using t-test with a significance level of can you say that the course has helped the students in enhancing their language capability? Clearly write Ho and H1 and explain your result. Make suitable assumptions, if any.