hello, please help this question, (the R is 6, that means R=6), with very clear steps and explanation for it

The credit card debt of esh degree graduates of Country A follow a normal distribution with a population mean of {1554.400 and a standard deviation of USS [,200. (a) Find the probability that a randomly selected fresh degree graduate has a credit card debt between US$3.200 and US$(5,000 + 20 x R). Correct your answer to 4 decimal places. (3 marks) Find the probability that the sample mean of credit card debt of 25 randomly selected fresh degree graduates is greater than US$(4,700 + 10 x R). Correct your answer to 4 decimal places. (3 marks) Find the (2 x R + 70)"' percentile of the distribution of credit card debt of esh degree graduates. Correct your answer to the nearest integer. (4 marks)