Reference no: EM13110232
1. Z-test
A researcher wishes to test the claim that the average age of lifeguards in Ocean City is greater than 24 years. She selects a sample of 36 guards and finds the mean of the sample to be 24.7 years with a standard deviation of 2 years. Is there evidence to support her claim at a 95% level of confidence?
2. T-test for Unpaired data
Consider the following situation describing layoffs at a manufacturing plant of the Monsanto Company. Does there appear to be a case of age discrimination between those laid off and those non-laid off?
Employee age layoff status
1 51 no
2 58 no
3 48 no
4 53 yes
5 45 yes
6 43 yes
7 49 no
8 59 no
9 56 yes
10 56 yes
11 54 no
12 55 yes
13 54 no
14 48 no
15 39 no
16 47 no
17 59 yes
18 58 no
19 55 yes
20 57 yes
21 57 yes
22 53 no
(Gregory L. Harper, "Statistics as evidence of age discrimination," The hastings law journal, vol 32, may 1981, pp. 1347-1375)
3. Z-test
A physician claims that joggers maximal volume oxygen uptake is greater than the average of all adults. A sample of 15 joggers has a mean of 40.6 milliliters per kilogram and a standard deviation of 6 ml/kg. If the average of all adults is 36.7 ml/kg, is there enough evidence to support the physician's claim at 95%?
4. Word answer
Explain the difference between testing a single mean and testing the difference between two means
5. Chi-square
The advisor of an ecology club at a large college expects that the group consists of 10% freshman, 20% Sophomores, 40% Juniors and 30% Seniors. The membership for the club this year is observed to be 14 freshman, 19 sophomores, 51 Juniors and 16 Seniors. At 95% level of confidence, test the advisors belief.
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Calculate and interpret z- score for expenses
: If member of sales force submits the entertainment expense (dinner cost for four) of $190, must this expense be considered unusually high. Calculate and interpret z- score for each of six entertainment expenses.
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Mcq on critical value
: You want to determine if your widgets from machine 1 are the same as machine 2. Machine 1 has a sample mean of 50 and a population standard deviation of 5 and a sample size of 25.
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In which parent did the nondisjunction occur
: A man makes 0 units of an enzyme due to homozygous recessive genes on chromosome 21. His wife makes 100 units of the enzyme due to a heterozygous pair of genes on chromosome 21. They have a son with trisomy 21 who makes 200 units of the enzyme.
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Determining testing proportions
: A survey dating back to the 1990's suggested that Americans anticipated a reduction in living standards and that a steadily increasing consumption no longer might be as important as it was in the past. (Were they right?)
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Basic question of general statistics
: A researcher wishes to test the claim that the average age of lifeguards in Ocean City is greater than 24 years. She selects a sample of 36 guards and finds the mean of the sample to be 24.7 years with a standard deviation of 2 years. Is there evi..
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Compute probability to make purchase using binomial formula
: Assume that 6 customers enter store and that these customers make independent purchase decisions. Use binomial formula to compute probability that exactly five customers make purchase.
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Find optimal number of production runs per year
: The Ambrosia Bakery makes cakes for freezing and subsequent sale. The bakery, which operates five days a week, 52 weeks a year, can produce cakes at the rate of 116 cakes per day.
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Calculate economic value added
: Spencer Inc. has the following information for the current year: Net income = $600; Net operating profit after taxes (NOPAT) = $500; Total assets = $4,000.
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Conducting the test by using the p-value method
: Test at the 1% significance level whether currently all adult men spend less than 11 hours per week watching sports on tv. Calculate the p-value for this problem and conduct the test using the p-value method.
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