Question

In: Statistics and Probability

1. What SAMPLE SIZE is needed if a 2 lb. margin of error is required for...

1. What SAMPLE SIZE is needed if a 2 lb. margin of error is required for computing the 98% confidence interval of the mean weight of adult female otters? Assume a population standard deviation of 6 lbs.

2. BY HAND (i.e., calculate the margin of error from the formula), find the 90% confidence interval for the mean number of times people breathe per minute (bpm), given that a sample of 60 people had a mean rate of 9.3 bpm. Assume a population standard deviation of 1.5 bpm.

Expert Solution

1 ) Given : Margin of error=E=2

Population stnadard deviation=

Significance level=

Now , ; From standard normal distribution table

Therefore , the required sample size is ,

2.

Given : Sample size=n=60

Population stnadard deviation=

Significance level=

Now , ; From standard normal distribution table

Therefore , the margin of error is ,

Therefore , the 90% confidence interval for the mean number of timess people breathe per minute is ,

orchestra answered 2 years ago

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