1. Average monthly household expenditure as found in a survey is given as under: Average Monthly Expenses (in Rs)

15000 7005 7950 8001 9050
12000 11000 8500 9500 13000
6000 9200 10500 8900 12500
12100 14100 8100 9000 11900

Perform the following tasks on the data given above:
Enter the data in a spreadsheet software and create a frequency distribution in 8 equal ranges. Use array formula to create the distribution. Draw the histogram of the data. Find the mean and variance for the data using spreadsheet formula. How will the mean and variance change, if five more sample data are added to the current data? The five more sample data are
20000 19000 18000 12000 16000

2. A total of 400 sheep were selected for testing the effectiveness of a vaccine. The result of the study is given in the following table <img src='./qimages/10636-2.jpg'>

Use Chi-square test to determine if the vaccination helped in controlling the disease. Explain your results. Make suitable assumptions, if any.