Question

"A day care program has an average daily expense of $75.00. The standard deviation is $5.00. The owner takes a sample of 64 bills. What is the probability the mean of his sample will be between $70.00 and $80.00?"

Answer 1

their you go i had it wrong so thought i give someone the right answer

Explanation:

1.0

34

1.0

34

68

Answer 2

p=1

Explanation:

Given that a day care program has an average daily expense of $75.00. The standard deviation is $5.00.

Sample size = 64

Std error of sample =
`(5)/(√(64) ) \\=0.625`

Thus sample mean will follow normal with

(75, 0.625)

Required probability

=
`P(70<\bar x <80)\\\\= P(|z|<16)\\=1`

It is almost a certain event with p =1