The confidence interval was (57, 61) What was the point estimate?  What was the margin of error? You are interested in estimating the the mean age of the citizens living in your community. In order to do this, you plan on constructing a confidence interval; however, you are not sure how many citizens should be included in the sample. If you want your sample estimate to be within 4 years of the actual mean with a confidence level of 97%, how many citizens should be included in your sample? Assume that the standard deviation of the ages of all the citizens in this community is 22 years. (Use Excel to find the appropriate critical value and round it to 3 decimal places.)

Find the sample size need to find the Population Proportion if the margin of error is 4%, the confidence level is 99%, and the sample proportion is .41.

Find the confidence level and α for an 80​% confidence interval.

what sample size should a researcher take if he wants to estimate a population proportion to be 2% of the true value with 90% confidence

Determine whether the statement below makes sense or does not make sense. Explain clearly. Based on our sample, the 95% confidence interval for the mean amount of television watched by adults in a nation is 3.5 to 4.1 hours per day. Therefore, there is 95% chance that the mean for all adults in the nation will fall somewhere in this range and a 5% chance that it will not. Choose the correct answer below. O A. The statement makes sense. There is 95% probability that the confidence interval limits actually contain the true value of the population mean, so the probability it does not fall in this range is 100% - 95% = 5%. O B. The statement does not make sense. The probability the population mean is greater than the upper limit is 5% and the probability it is less than the lower limit is 5%, so the probability it does not is 5% + 5% = 10%. O C. The statement makes sense. There is 5% probability that the confidence interval limits do not contain the true value of the sample mean, so the…

do the last one please

Researchers studied the mean egg length (in millimeters) for a bird population. After taking a random sample of eggs, they obtained a 95% confidence interval of (45,60). What is the value of the margin of error? Choose the correct answer below. A. 15 mm B. 52.5 mm O c. 7.5 mm O D. 1.96

You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately 79.8. You would like to be 95% confident that your estimate is within 5 of the true population mean. How large of a sample size is required?