# Web Calculator Exercise 2

**Topics:**Normal distribution, Standard deviation, Statistics

**Pages:**3 (450 words)

**Published:**November 18, 2012

a. Mean age = 960/20=48

b. Standard Deviation = 10.74832

Web address: http://easycalculation.com/statistics/standard-deviation.php Frequency distribution table for denomination.

Score f(frequency)

1 1

2 2

4 2

5 1

6 3

7 3

8 1

9 3

10 3

12 1

N=30

c. What is the percentage of people who identify themselves as Baptist?

3/20 = .15 x 100 = 15%

What is the mode of church attendance?

5

Question 2

a. What is the Z score for a car with a price of $33,000?

Z=2.85714286

b. What is the Z score for a car with a price of $30,000?

Z=2

Web address for calculator: http://www.danielsoper.com/statcalc3/calc.aspx?id=22

c. At what percentile rank is a car that sold for $30,000?

97.72%

Web calculator used: http://easycalculation.com/statistics/zscore-to-percentile.php

3. One student’s Math score was 70 and the same individual’s English score was 84. On which exam did the student do better?

Math: +3 points divided by 9.58 SD = .3132

English: + 6 points divided by 12.45 SD = .482

The student did better on the English test.

4.Suppose you administered an anxiety test to a large sample of people and obtained normally distributed scores with a mean of 45 and standard deviation of 4. Do not use web-calculator to answer the following questions. Instead, you need to use the Z distribution table in Appendix A in Jackson’s book.

a.If Andrew scored 45 on this test. What is the Z score?

Z=45-45 z=0

4

b. If Anna scored 30 oh this test. What is her Z score?

Z=30-45 Z=-3.75

4

c.If Bill’s Z score was 1.5, what is his real score on this test?

1.5 = x-45 X=51

4

d.There are 200 students in a sample. How many of these students will have scores that fall under the score of 41?

Z=41-45 Z= -1 According to Appendix A .159 x 200 Answer = 31.8 fall under 41 4...

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