Get reliable answers to your questions at Westonci.ca, where our knowledgeable community is always ready to help. Get expert answers to your questions quickly and accurately from our dedicated community of professionals. Experience the convenience of finding accurate answers to your questions from knowledgeable experts on our platform.

The starting salary of business students in a university is known to be normally distributed. A random sample of 18 business students results in a mean salary of $46,500 with a standard deviation of $10,200. Construct the 90% confidence interval for the mean starting salary of business students in this university. Multiple Choice 46,500 ± 1.740 ( 10,200 / 18−−√ ) 46,500 ± 1.330 ( 10,200 / 18−−√ ) 46,500 ± 1.734 ( 10,200 / 18−−√ ) 46,500 ± 1.645 ( 10,200 / 18−−√ )

Sagot :

Answer:

[tex]46500 \pm 1.74\frac{10200}{\sqrt{18}}[/tex]

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 18 - 1 = 17

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 17 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 1.74

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 1.74\frac{10200}{\sqrt{18}}[/tex]

Confidence interval:

Sample mean plus/minus margin of error. So

[tex]46500 \pm 1.74\frac{10200}{\sqrt{18}}[/tex]