Find the necessary sample size.Weights of women in one age group are normally distributed with a standard deviation of 10.43 kg. A researcher wishes to estimate the mean weight of all women in this age group.Find how large a sample must be drawn in order to be 95% confident (use z=2) that the sample mean will not differ from the population mean by more than 1.30 kg.

A random sample of 12 items is taken and is found to have a meanweight of 50 grams and a standard deviation of 9 gramsWhat is the mean weight of population1. with 95% confidence2. with 99% confidence

You measure 42 textbooks' weights, and find they have a mean weight of 72 ounces. Assume the population standard deviation is 8.9 ounces. Based on this, construct a 95% confidence interval for the true population mean textbook weight.[Note: z-test statistic critical value needs to be used since the population standard deviation is given.]Give your answers as decimals, to two places[,]

A study was commissioned to find the mean weight of the residents in certain town. The study examined a random sample of 127 residents and found the mean weight to be 151 pounds with a standard deviation of 21 pounds. At the 95% confidence level, use the normal distribution/empirical rule to estimate the margin of error for the mean, rounding to the nearest tenth.

A sample of size =n90 is drawn from a normal population whose standard deviation is =σ9.7. The sample mean is =x38.78.Part: 0 / 20 of 2 Parts CompletePart 1 of 2(a) Construct an 80% confidence interval for μ. Round the answer to at least two decimal places.An 80% confidence interval for the mean is <<μ.

A population's standard deviation is 12. We want to estimate the population mean with a margin of error of 2, with a 95% level of confidence. (Use t Distribution Table & z Distribution Table.)How large a sample is required? (Round your intermediate calculations to 2 decimal places and round up your answer to the next whole number.)