Question

Suppose x has a distribution with a mean of 80 and a standard deviation of 45. Random samples of size n = 36 are drawn.

(a)

Describe the  distribution.

has a binomial distribution. has an unknown distribution.     has an approximately normal distribution. has a Poisson distribution. has a normal distribution. has a geometric distribution.

Compute the mean and standard deviation of the distribution. (For each answer, enter a number.)

= mu sub x bar =

= sigma sub x bar =

(b)

Find the z value corresponding to  = 95. (Enter an exact number.)
z =

(c)

Find P( < 95). (Enter a number. Round your answer to four decimal places.)
P( < 95) = P(x bar < 95)

(d)

Would it be unusual for a random sample of size 36 from the x distribution to have a sample mean less than 95? Explain.

Yes, it would be unusual because more than 5% of all such samples have means less than 95.No, it would not be unusual because less than 5% of all such samples have means less than 95.    No, it would not be unusual because more than 5% of all such samples have means less than 95.Yes, it would be unusual because less than 5% of all such samples have means less than 95.

Answer 1