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In: Statistics and Probability

1. Compute the sample standard deviation of the following data: x1 = 12,x2 = 7,x3 =...

1. Compute the sample standard deviation of the following data: x1 = 12,x2 = 7,x3 = 6,x4 = 8,x5 = 9.
A. ≈ 2.3 B. ≈ 2.6 C. ≈ 5.3 D. ≈ 6.8 E. other value
2. Suppose a simple random sample of size 16 from a normal population yields observed statistics of x¯ = 15.7 and s = 3.8. Find a 99% confidence interval for the population mean µ.
A. [12.81,18.59] B. [12.9,18.50] C. [12.93,18.47] D. [13.25,18.15] E. other value
3. Suppose that of 300 people polled 225 of them say they plan retire by age 65. Find a (two-sided) 98% confidence interval for number of people who plan to retire by age 65.
A. [.699,.802] B. [.696,.804] C. [.692,.808] D. [.686,.815]
4. How many people would you have to poll to be 97% sure that your margin of error will be less than 6%?
A. 328 B. 378 C. 543 D. 666 E. other value
The next three questions are based on the following data on the girth (in inches) and the height (in feet) of black cherry trees. Treat the girth as the independent/explanatory variable.
Girth 8.6 10.5 11.3 12.9 13.3 Height 65 72 79 85 86

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