A research team takes the weights of what they believe to be a representative sample of...

A research team takes the weights of what they believe to be a representative sample of 30 adult female great whites. They find that the sample has a mean weight of 2050 pounds and a standard deviation of 220 pounds.

a.Find a 99% confidence interval for the mean weight of all adult female great whites.

b.Old statistics books used to say that if a sample size was at least 30, students could use a normal distribution instead of a t-distribution. Find the percent decrease in the width of the confidence interval for this problem if a student uses a normal curve instead of a t-distribution.

c.A previous paper had published that the mean weight of adult female great weights is 1950 pounds. If the researchers wanted to conduct an inference test against this parameter, find the p-values they would get if the researchers form a directional hypothesis (?>1950) versus a nondirectional hypothesis (?≠1950).

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orchestra answered 1 year ago

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