7- In worksheet 3, a dataset from blood bank is presented. The data are recorded for apheresis blood donation made by a group of donors of a period of time. The donor ID is unique for each donor. A donor might have donated more than once in this period. At each donation, the blood total protein level of the donor has been recorded. Use the dataset to answer the following questions:

a) There are some missing values for blood type. Think how you can fill in the missing values. Explain your approach (step by step) and also apply your approach and try to fill the missing value as much as possible in. (save the results in an Excel worksheet in and name it Question 3 Part a.)

b) Calculate the average of total protein for each blood type. Explain your approach (step by step). Report them in a worksheet and name it Question 3 Part b.

c) Calculate the range of total protein for each blood type. Explain your approach (steps by step). Report them in a worksheet and name it Question 3 Part c.

d) Is total protein declining by age?

e) Present two best visualisation tool for this data that you think provide useful information?