A sample of 25 randomly English majors has a mean test score of 81.5 with a standard deviation of 10.2. Construct a 95% confidence interval for the population mean, µ. Assume the population has a normal distribution. Round to four decimal places when necessary. Point Estimate = [ Select ] Margin of Error E = [ Select ] Lower, Upper Limit = [ Select ] >

Babies: A sample of 25 one-year-old girls had a mean weight of 24.1 pounds with a standard deviation of 4.3 pounds. Assume that the population of weights is normally distributed. A pediatrician claims that the standard deviation of the weights of one-year-old girls is greater than 7 pounds. Do the data provide convincing evidence that the pediatrician's claim is true? Use the =α0.05 level of significance.

Consider a set of data in which the sample mean is 30.230.2 and the sample standard deviation is 7.87.8. Calculate the z-score given that x=31.4x=31.4. Round your answer to two decimal places.

A normal distribution has a mean of 130 and a standard deviation of 10. Find the z-score for a data value of 112. Round to two decimal places

A researcher collects data that represents the average number of hours of sleep in the last two nights by 8 depressed patients and 9 non-depressed patients. The researcher is interested in whether the two groups reliably differ in the amount of sleep they get.     Use Jamovi to calculate t-obt and the p value.

A normal distribution has a mean of 147 and a standard deviation of 4. Find the z-score for a data value of 133. Round to two decimal places

A normal distribution has a mean of 136 and a standard deviation of 10. Find the z-score for a data value of 141.Round to two decimal places

The heights of people in a certain population are normally distributed with a mean of 68 inches and a standard deviation of 4.4 inches. Suppose that a normal model applies.   The model that correctly shows the 68-95-99.7 rule (empirical rule) for tree diameter is model:           B C     A About 68% of heights fall in the range described by option between 59.2 and 76.8. below 63.6.     between 54.8 and 81.2. between 63.6 and 72.4. above 72.4. What percent of people in this population have heights below 59.2?  %_

A distribution of values is normal with a mean of 100.9 and a standard deviation of 60.6.Find P72, which is the score separating the bottom 72% from the top 28%.