# one sample test hypothesis

• Jun 1st 2008, 04:45 PM
EquinoX
one sample test hypothesis
A statewide real estate sales agency, Farm Associates, specializes in selling farm property in the state of Nebraska. Their records indicate that the mean selling time of farm property in the state of Nebraska. Their records indicate that the mean selling time of farm property is 90 days. Because of recent drought conditions, they believe that the mean selling time is now greater than 90 days. A statewide survey of 100 farms sold recently revealed that the mean selling time was 94 days, with a standard deviation of 22 days. At the .10 significance mean level, has there been an increase in selling time?

My questions:
1. Is the null hypothesis is when the mean is <= 90 and the alternative hypothesis is > 90?
2. What is the critical z-value? I got 1.28, is this right?
3. Is this a two tail test or one tail test? I am guessing it's one tail test
4. I got the z value to be 1.818 is this right?

• Jun 1st 2008, 05:13 PM
galactus
You appear to be on the right path. The test statistic and the critical value are correct.

$H_{0}:{\mu}\leq{90}$
$H_{a}:{\mu}>90, \;\ \text{claim}$

With the data generated, we can see that the test stat falls in the rejection region. That is, the test stat > critical value. Therefore, we reject the null hypothesis. The alternate is the claim, so what does that tell you?.
• Jun 1st 2008, 06:54 PM
EquinoX
therefore there has been an increase in selling time? right?