a) The weekly wages of employees of Volta gold are normally distributed about a mean of $1,250 with a variance of $120. Find the probability of an employee having a weekly wage lying;

i) Between $1,320 and $970

ii) Under $1,400

iii) Over $1,290

b) An achievement test was administered to a class of 20,000 students. The mean score was 80 and the standard deviation was 11. If Lingard scored 72 in the test, how many students did better than him?

c) List the two main data collection methods, and give two advantages and two disadvantages for eachd) List two probability sampling techniques and two non-probability sampling techniques. Briefly explain eache)  Differentiate between Inferential statistics and descriptive statistics