A bank has kept records of the checking balances of its customers ...

[V@ndy87]

A bank has kept records of the checking balances of its customers and determined that the average daily balance of its customers is 300 with a standard deviation of 48 . A random sample of 144 checking accounts is selected.
 a. What is the probability that the sample mean will be more than 306.60?
  b. What is the probability that the sample mean will be less than 308?
  c. What is the probability that the sample mean will be between 302 and 308?
  d. What is the probability that the sample mean will be at least 296?

Question 2

For a standard normal distribution, a negative value of z indicates _____.
 a. a mistake has been made in computations, because z is always positive
  b. the area corresponding to the z is negative
  c. the z is to the left of the mean
  d. the z is to the right of the mean

[bfulkerson77]

Answer to Question 1

a. .0495
b. .9772
c. .2857
d. .8413

Answer to Question 2

c

[V@ndy87]

Wow, this really help

[ebonylittles]

Great answer, keep it coming