Statistics questions
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Apply the applicable rule before solving any problem. Show the formula, and graph where applicable.
1a) Sx is a known estimate: True or False
1b) Population mean is a known estimate: True or False
1c) The objective of a confidence interval is not to bracket the fixed population mean: True or False
1d) T-test discusses the deviation of a random variable from its mean measured in standard deviation of the sample mean units: True or False
1e) T-test is used to test a hypothesis about the population mean: True or False
Standard Normal Probability Distribution
2) Find the probability that the random value of Z is between +.65 and +.2.33.
T distribution is symmetric and t table gives values of t such that the probability of the larger t is equal to a given probability.
3a) P(t > to) = 0.10 given a sample size of 13. Find to
3b) P(-to > t > + to) = 0.05 given a sample size of 9. Find to
3c) P(t < 2.1098) = ? given a sample size of 18. Find the associated probability.
Consider the probability that a random interval x ± (t.05)S will contain the fixed μ (population mean) is .95 That is:
P( – t.05S ≤ μ ≤ + t.05S) = .95.
4) Construct a Confidence Interval given the following: Sample size = 10, = 131, S2 = 971.11.
T test: 5) If a real estate market is strong, there will be a close relationship between the asking price for homes and the selling price. Suppose that one analyst believes that the mean difference between asking price and selling price for homes in a particular market area is less than $2000. To test this using an alpha level equal to .05, random sample of n=15 homes that have sold recently was selected. The difference between asking price and selling price data from the sample is in the following:
What should we conclude about the analysts claim? Solve the test statistic approach. Use the following statistics to solve the problem. n = 15 = $1831.067 S = $506.59
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