A laboratory tested 78 chicken eggs and found that the mean amount of cholesterol was 224 milligrams with s = 14.7 milligrams. Find the 95% confidence interval.

Mrs. Gallas wanted to estimate the average weight of an Oreo cookie to determine if theaverage weight was less than advertised. She selected a random sample of 30 cookies andfound the weight of each cookie (in grams). The mean weight was = 11.1921 grams with astandard deviation of sx = 0.0817 grams. Make a 95% confidence interval to estimate the truemean weight of an Oreo.   1. What is the formula for calculating the standard deviation of the sampling distribution of x? 2.What condition must be met to use this formula? Has it been met?

In one city, 27.8% of the 9000 students surveyed said they eat at the school cafeteria. Find the 95% confidence interval for the proportion of students that said they eat at the school cafeteria. Give answer as a percent rounded to one decimal place.

A RESEARCH FIRM CONDUCTED A SURVEY TO DETERMINE THE MEAN AMOUNT AMERICANS SPEND ON COFFEE DURING A WEEK. THEY FOUND THE DISTRIBUTION OF WEEKLY SPENDING FOLLOWED THE NORMAL DISTRIBUTION WITH A POPULATION STANDARD DEVIATION OF $5. A SAMPLE OF 64 AMERICANS REVEALED THAT X = 20. WHAT IS THE 95% CONFIDENCE INTERVAL ESTIMATE OF THE MEAN? ESTIMATE TO 3 DECIMAL POINTS.

A random sample of 300 college freshmen found that 112 of them own an iPhone. Find a 95% confidence interval for the true proportion of college freshmen that own an iPhone. Show all work leading up to your answer below.

Find the lower limit of 95% confidence interval.    An SRS of 36 students were taken from high schools in a particular state. The average test score of the sampled students was 60 with a standard deviation of 13.26. Give the lower limit of the interval approximation.

4) A producer of various kinds of batteries has been producing "D" size batteries with a life expectancy of 87 hours. Due to an improved production process, management believes that there has been an increase in the life expectancy of their "D" size batteries. A sample of 36 batteries showed an average life of 88.5 hours. Assume from the past information that it is known that the standard deviation of the population is 9 hours. A) Give the null and the alternative hypothesis. B) Compute the test statistic. C) At 99% confidence using the critical value approach, test management's belief. D) What is the p-value associated with the sample results? What is your conclusion based on the p-value? Note α = 0.05.

A random sample of 47 cars in the drive-thru of a popular fast food restaurant revealed an average bill of $17.51 per car. The population standard deviation is $6.05. Estimate the mean bill for all cars from the drive thru with 91% confidence.

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?

Find z* for a confidence level of 83%. Give your answer to 3 decimal places.