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within_of the population mean /jl. rui m tne DianK.

(c) About 95% of all samples will capture the true mean of all of the invoices in the interval x plus or minus_. Fili in the blank.

6.6 You measure the weights of 24 małe runners. You do not actually choose ar SRS, but you are willing to assume that these runners are a random sampie from the population of małe runners in your town or city. Here are their weights in kilograms:

67.8	61.9	63.0	53.1	62.3	59.7	55.4	58.9
60.9	69.2	63.7	68.3	64.7	65.6	56.0	57.8
66.0	62.9	53.6	65.0	55.8	60.4	69.3	61.7

Suppose that the standard deviation of the population is known to be a = 4.5 kg.

(a)    What is cr_F, the standard deviation of x? g

(b)    Give a 95% confidence interval for fi, the mean of the population from which the sample is drawn. Are you quite surę that the average weight of the population of runners is less than 65 kg?

6.7 Crop researchers plant 15 plots with a new variety of com. The yiełdsin bushels per acre are