A random sample of 10 children found that their average growth for the first year was 9.8 inches, with a standard deviation of 0.96 inches. Find the 85% confidence interval of the mean growth of all American children in the first year of life. What is the name of the confidence interval? One Proportion z Interval One Sample z Interval Two Proportion z Interval Chi-Square Goodness of Fit Interval Correlation t Interval Two Independent Samples t Interval Chi-Square Interval for Independence ANOVA One Sample t Interval Paired Samples t Interval

Suppose you take a random sample of n = 80 Douglas College students and ask each student their age. You find that the mean age of students in this sample is X = 22.0375 years and the sample standard deviation is s = 3.2014 years.  Fill in the blanks (rounding to four decimal places):  The 95% confidence interval for the mean age μ of all Douglas College students is from ______ years to ______ years.

you measure the weights of a random sample of twenty-five people. The sample mean is 60 kg. Suppose that the mean weights of people follow a normal distribution with an unknown mean and standard deviation of 5 kg. You compute a 95% confidence interval for μ. The 95% confidence interval for μ is?

The Pizza Shop wanted to determine what proportion of its customers ordered only cheese pizza. Out of 80 customers surveyed, 15 ordered cheese pizza. They want a 99% confidence interval of the true proportion of customers who order only cheese pizza. Which type of confidence interval should we use here? a confidence interval for the mean using a table value from the standard normal distribution. a confidence interval for the mean using a table value from the t distribution. a confidence interval for a proportion using a table value from the standard normal distribution. a confidence interval for proportion using a table value from the t distribution.

Tina catches a 14-pound bass.  She does not know the population mean or standard deviation.  So she takes a sample of five friends and they say the last bass they caught was 9, 12, 13, 10, and 10 pounds.  Find the t and calculate a 95% (α = .05) confidence interval.

The distribution of study times for first year students follows a Normal distribution with standard deviation σσ = 54 minutes. Suppose a sample of 487 students found that the mean study time for these students was x¯x¯= 173 minutes per week. Use this to find a 88.28% confidence interval to estimate the mean study time for all students. We are 88.28% confident that the mean study time for first year students is between minutes_____ and ____  minutes.   What is the margin of error for your confidence interval?

The distribution of study times for first-year students follow a Normal distribution with a standard deviation σ = 48 minutes. Suppose a sample of 344 students found that the mean study time for these students was x¯= 170 minutes per week. Use this to find a 94.38% confidence interval to estimate the mean study time for all students. We are 94.38% confident that the mean study time for first-year students is between the following ( answer) minutes and  ( answer) minutes. The answer needs to be the mean study time for first-year students is between what amount of minutes and the following minutes.

Girls ?̅ = 30.4 hg ? = 7.1 hg ? = 205 Boys ?̅ = 30.4 hg ? = 7.1 hg ? = 205 In a study on birth weights, the following summary statistics are found:Use a 95% confidence level to construct the confidence interval estimates of the mean for each set of summary statistics.Which score (? or ?) should be used as the critical value? __________________The confidence interval for the birth weight of girls is __________________ < ? < _________________.The confidence interval for the birth weight of boys is _________________ < ? < _________________.Does it appear that boys and girls have very different birth weights? Support your answer.

For a sample, a score that is 12 points above the mean has a z-score of z = 1.20. What is the sample standard deviation?

How much do students pay, on the average, for textbooks during the first semester of college? From a random sample of 400 students the mean cost was found to be $357.75, and the sample standard deviation was $37.89. Assuming that the population is normally distributed, find the margin of error of a 95% confidence interval for the population mean.