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# Quantitative Methods (5 Stats Problem)

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I need help with the included statistics problems. These are practice problems and I am unable to get a good grasp in this area.

11. Given the following data on the number of pints of ice cream sold at a local ice cream store for a 6-period time frame:
Period Demand
1 200
2 245
3 190
4 270
5 280
6 300
Compute a 3-period moving average for period 4.

12. The following data summarizes the historical demand for a product

Month Actual demand
March 20
April 25
May 40
June 35
July 30
August 45

Use a four period moving average and determine the forecasted demand for July and August.

13. The following data summarizes the historical demand for a product

Month Actual demand
March 20
April 25
May 40
June 35
July 30
August 45

Use exponential smoothing with and the smoothed forecast for July is 32 and determine August and September's smoothed forecasts.

14. The following sales data are available for 1998-2003 inclusive:
Year Sales
1998 7
1999 12
2000 14
2001 20
2002 16
2003 25
Determine a 4-year moving average forecast for each possible year.

15. Robert has the following accounts on money spent on gambling and winnings:
Money spent Money won
1000 2500
1200 4000
11800 4500
2000 4600
2500 5000
2800 4800
3500 5600
4000 6000
4200 5800
7000 X
Using linear regression, predict x.

https://brainmass.com/statistics/central-tendency/quantitative-methods-5-stats-problem-67017

#### Solution Summary

This solution calculates the period moving average, forecasted demand, exponential smoothing, and uses linear regression to compute the value of 'x'.

\$2.19

## Mean, Median, Sum of Squared Deviations, Variance, and Standard Deviation

I had to do 100 problems. These are the ones left. I have no strength or understanding of what or how to do them. Please HELP!

For the following scores, find the (a) mean, (b) median, (c) sum of squared deviations,(d) variance, and (e) standard deviation:2, 2, 0, 5, 1, 4, 1, 3, 0, 0, 1, 4, 4, 0, 1, 4, 3, 4, 2, 1, 0

For the following scores, find the (a) mean, (b) median, (c) sum of squared deviations,
(d) variance, and (e) standard deviation: 1,112; 1,245; 1,361; 1,372; 1,472

For the following scores, find the (a) mean, (b) median, (c) sum of squared deviations,
(d) variance, and (e) standard deviation:
3.0, 3.4, 2.6, 3.3, 3.5, 3.2

A psychologist interested in political behavior measured the square footage of the desks in the official office of four U.S. governors and of four chief executive officers (CEOs) of major U.S. corporations. The figures for the governors were 44, 36, 52, and 40 square feet. The figures for the CEOs were 32, 60, 48,and 36 square feet. (a) Figure the mean and standard deviation for the governors and for the CEOs. (b) Explain what you have done to a person who has never had a course in statistics. (c) Note the ways in which the means and standard deviations differ, and speculate on the possible meaning of these differences, presuming that they are representative of U.S. governors and large corporations' CEOs in general.

On a standard measure of hearing ability, the mean is 300 and the standard deviation is 20. Give the Z scores for persons who score (a) 340, (b) 310, and (c)260. Give the raw scores for persons whose Z scores on this test are (d) 2.4, (e) 1.5, (f) 0, and (g) 4.5.

A person scores 81 on a test of verbal ability and 6.4 on a test of quantitative ability. For the verbal ability test, the mean for people in general is 50 and the standard deviation is 20. For the quantitative ability test, the mean for people in general is 0 and the standard deviation is 5. Which is this person's stronger ability: verbal or quantitative? Explain your answer to a person who has never had a course in statistics.

Suppose you want to conduct a survey of the attitude of psychology graduate students studying clinical psychology towards psychoanalytic methods of psychotherapy. One approach would be to contact every psychology graduate student you know and ask them to fill out a questionnaire about it. (a) What kind of sampling method is this? (b) What is a major limitation of this kind of approach?

You are conducting a survey at a college with 800 students, 50 faculty members, and 150 administrative staff members. Each of these 1,000 individuals has a single listing in the campus phone directory. Suppose you were to cut up the directory and pull out one listing at random to contact. What is the probability it would be (a) a student, (b) a faculty member, (c) an administrative staff member, (d) a faculty or administrative staff member, and (e) anyone except administrative staff member? (f) Explain your answers to someone who has never had a course in statistics.

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