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Simple Queries on Statistics

1.The relationship among the mean, median, mode in symmetric distribution is...
In mean, median, mode and standard deviation which measures of central tendency are not affected by extremely low or extremely high values.
In a simple linear regression problem, r and b1 (have opposite signs/must have same signs/must have opposite signs/are equal).
The coefficient of determination (r2) tells us

2.In the age of 26, 30, 24, 32, 32, 31, 27 & 29, the distribution of age data is (symmetric/bell-shaped/skewed to left/skewed to right).

3.An insurance sales representative has an appointment with four clients today. From, long experience, she knows that the probability of selling a policy to a client is 0.80. What is the probability of selling a policy to all 4 clients?

4.The mean life of certain type of refrigerator is approximately normally distributed with a mean of 7 years and a standard deviation of 2 years. What proportion of the refrigerators last 10 years?

5.A survey is planned to determine the average annual family medical expenses of employees of a large company. The management of the company wishes to be 95% confident that the sample average is correct to within ± $50 of the true average family medical expenses. A pilot study indicates that the standard deviation can be estimated as $400. How large a sample size is needed?

6.A grocery store owner is interested in determining if the average weight of a package of ground beef sold in the store weighs one pound. An appropriate null hypothesis for this study is

7.Given the time series trend equation Y¿ = 25 + 0.6t (base year = 2000), what would be the forecast value for 2005 starting with the base period as t = 1.

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Solution Summary

The solution explains what the coefficient of determination tells us, and gives a skewed data analysis.

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