Suppose x has a distribution with a mean of 90 and a standard deviation of 27.
Suppose x has a distribution with a mean of 90 and a standard deviation
of 27. Random samples of size n = 36
are drawn.
(a) Describe the x distribution
and compute the mean and standard deviation of the distribution.
x
has
—Select—
a binomial
an unknown
a normal
an approximately normal
a Poisson
a geometric
distribution with mean μx =
and standard deviation σx = .
(b) Find the z value corresponding to x = 99.
z =
(c) Find P(x < 99).
(Round your answer to four decimal places.)
P(x < 99) =
(d) Would it be unusual for a random sample of size 36 from the x distribution to have a sample mean less than 99? Explain.
No, it would not be unusual because less than 5% of all such samples have means less than 99.
Yes, it would be unusual because more than 5% of all such samples have means less than 99.
Yes, it would be unusual because less than 5% of all such samples have means less than 99.
No, it would not be unusual because more than 5% of all such samples have means less than 99.