Friday

August 29, 2014

August 29, 2014

Posted by **Carolyn** on Wednesday, November 14, 2012 at 11:48am.

444, 497, 502, 517, 532, 559, 568, 598, 611, 636,

637, 657, 681, 681, 693, 698, 701, 708, 711, 713,

714, 714,714, 739, 741, 743, 745, 753, 755, 768,

768, 781, 787, 792, 793, 797, 797, 809, 835, 836

Answer the question below.

(1) Calculate the mean and variance of this data set.

(2) The local bank requires that the applicant has a score of at least 600 in order to qualify for a certain low-rate mortgage. If one applicant is randomly selected from the sample above, what is the probability that the applicant is qualified for the low-rate mortgage?

(3) Assume that FICO score of all people in the United States have a normal distribution, and also assume that the mean and variance you calculated in question (1) are representative of the population mean and variance, respectively. If one person is randomly selected from the population, what is the probability that his/her score is at least 600?

(4) Under the assumption of (3), if 9 people are randomly selected from the population, what is the probability that they have an average score of at least 600?

- statistics -
**PsyDAG**, Wednesday, November 14, 2012 at 12:40pm(1) Find the mean first = sum of scores/number of scores

Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.

(2,3) Z = (score-mean)/SD

Standard Deviation = square root of variance

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to your Z score.

I'll let you do the calculations.

- statistics -
**dd**, Wednesday, November 14, 2012 at 11:36pmxc

**Related Questions**

Statistics - Verifying Requrements and finding the margin of error Credit rating...

Statistics - When consumers apply for credit, their credit is rated using the ...

Statistics - 1. A simple random sample of FICO credit rating scores is listed ...

statistics - 5. The table below shows Psychology exam scores, Statistics Exam ...

Statistics - For a population with a mean of µ=60 and standard deviation of &#...

statistics - Calculate SS, variance, and standard deviation for the following ...

statistics - In an extensive study involving thousands of British children, ...

statistics - Below are six data sets with 6 randomly selected scores in each ...

statistics - 5. The table below shows Psychology exam scores, Statistics Exam ...

statistics - Calculate SS, variance, and standard deviation for the following ...