the mean square area of several thousand apartments in a new development is advertised to be 1200 square feet. a tenant group thinks the apartments are smaller, on average, than advertised. the result of sampling 9 apartments yields a sample mean of x=1160 and sample standard deviation s = 120 feet. the histogram shows that the sampling distribution is approximately normal.) carry out the hypothesis test at significance level 0.01 via the following: state the null and alternative hypotheses, derive the test statistic, and state a conclusion in real world terms. (you can use the fact that the area to the left of -2.8965 is 1%, using the t distribution with 8 df)

We conclude that apartments are 1200 square feet, on average, as advertised.

Step-by-step explanation:

We are given the following in the question:  

Population mean, μ = 1200 square feet

Sample mean, = 1160

Sample size, n = 9

Alpha, α = 0.01

Sample standard deviation, s = 120

First, we design the null and the alternate hypothesis

We use one-tailed t test to perform this hypothesis.

Formula:

Putting all the values, we have

Now,

Since,                    

We fail to reject the null hypothesis and accept the null hypothesis.

Thus, we conclude that apartments are 1200 square feet, on average, as advertised.

the answer is d

step-by-step explanation:

a. she will receive a refund of $278.

step-by-step explanation: