The following data represents the grades of a sample of 12 students in statistics and economics as follows
|
Math grade
|
A
|
C
|
B
|
B
|
D
|
B
|
F
|
F
|
D
|
C
|
B
|
C
|
|
Economic Grade
|
B
|
F
|
C
|
B
|
C
|
A
|
C
|
F
|
B
|
B
|
A
|
C
|
Calculate the correlation between the student's grade in math and economics. What its type and strength.
The balances of all saving accounts at a local bank have a normal distribution with its mean equal to $ 12450 and standard deviation equal to $ 4160. Find the probability that the mean of a sample of 50 saving accounts selected from this bank will be
More than $ 11500.
Within $ 1500 of the population mean.
Find the number of accounts which will have an account of more than the population mean by at least $ 1000.
A charity believes that when it puts out an appeal for charitable donations the donations it receives will normally distributed with a mean $ 50 and standard deviation $ 6, and it is assumed that donations will be independent of each other.
Find the probability that the first donation it receives will be greater than $ 60.
Find the value X such that 5% of donations are more than $ X.