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(CLT for averages, unknown underlying distribution) The average monthly rental p

ID: 3051682 • Letter: #

Question

(CLT for averages, unknown underlying distribution) The average monthly rental price of a one-bedroom apartment in Bellingham is $804, with a standard deviation of $139. The distribution is unknown. Suppose we take 40-apartment averages of prices. Please answer the following questions:

(a) X-bar ~ ?

(b) What is the probability that a 40-apartment sample that we take has an average price below $800?

(c) Whereas we can answer a question like question (b) with 40-apartment averages, we can't, in this case, with 5-apartment averages. Very briefly explain why not.

Explanation / Answer

a) X-bar ~ 804

b)

probability that a 40-apartment sample that we take has an average price below $800

c) as from CLT; to assume normality for distribution other than normal sample size should be at least 30.

while a sample size of 40 fullfills that requirement but nt sample size 5.

for normal distribution z score =(X-)/ here mean=       = 804.000 std deviation   == 139.0000 sample size       =n= 40 std error=x=/n= 21.9778