Question

In: Statistics and Probability

To estimate the mean size of maple trees in a certain area of the Adirondacks, a...

  1. To estimate the mean size of maple trees in a certain area of the Adirondacks, a simple random sample of 20 maple tree heights is collected (assume the population of tree heights is normally distributed). Please refer to the data set for your tree heights.

24

47

52

58

41

37

56

63

39

32

24

29

52

33

47

40

56

52

54

31

a) Using the formula for confidence intervals, create a 95% confidence interval for the population mean of maple tree heights.

b) Using the formula for confidence intervals, create a 98% confidence interval for the population mean of maple tree heights.

c) What size sample would you need to estimate the population average heights of the maple trees with an error of 0.1 feet at a 90% level of confidence? Assume population standard deviation is 10.2 feet.

Solutions

Expert Solution

Xi (Xi-Xbar)2
24 374.4225
47 13.3225
52 74.8225
58 214.6225
41 5.5225
37 40.3225
56 160.0225
63 386.1225
39 18.9225
32 128.8225
24 374.4225
29 205.9225
52 74.8225
33 107.1225
47 13.3225
40 11.2225
56 160.0225
52 74.8225
54 113.4225
31 152.5225
867

2704.55


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