The length of human pregnancies from conception to birth varies according to a distribution that is approximately Normal with a m days and standard deviation 16 days. Suppose we choose an SRS of 6 pregnant women. Let = the m pregnancy length for the sample. What is the mean of the sampling distribution of ?

What is the SD of a distribution if the mean is 4.5 and a z score of 3.5 corresponds to a raw score of 15?

Suppose that the lengths of pregnancies are normally distributed with a mean of 271 days and a standard deviation of 10 days.  find the percentage of pregnancies that are longer than 254 days. For your intermediate computations, use four or more decimal places. Give your final answer to two decimal places (for example 98.23%).

Assume the average amount of caffeine consumed daily by adults is normally distributed with a mean of 260 mg and a standard deviation of 48 mg. In a random sample of 600 ​adults, how many consume at least 320 mg of caffeine​ daily?

Use the 95% rule and the fact that the summary statistics come from a distribution that is symmetric and bell-shaped to find an interval that is expected to contain about 95% of the data values.A bell-shaped distribution with mean 220 and standard deviation 24.The interval is to .

Assume that IQ scores follow a Normal distribution with µ=100 and σ=16.  Using our IQR rule for determining IQ score outliers, what IQ scores would establish the lower and upper fences for determining outliers?

How many adults must be randomly selected to estimate the mean FICO (credit rating) score of working adults in the United States. We want 99% confidence that the sample mean is within 3 points of the population mean. Assume that the population standard deviation is 68.

Marks obtained by students in an examination follow the normal distribution. If 30% of students got below 35 marks and 10% got above 60 marks. Find mean and standard deviation?

Acorns in the northern Atlantic regions of the U. S. have an average volume of 3.75 cubic centimeters, with a standard deviation of .85 centimeters. If we were to collect 1000 samples of 300 randomly-selected acorns, describe the sampling distribution for the sample mean of acorn volumes. Round to the nearest hundredth (two decimal places) if necessary. Shape: Center: Spread:

A random sample of 18 light bulbs is drawn from a normally distributed population. The population has mean and standard deviation are 517 hours and 39 hours, respectively. What is the mean of the sampling distribution the sample mean?