MODULE 12: Calculating the Small-Sample Confidence Interval Estimate for Mean when o is unknown Individual work. Directions: Solve the following problem individually. Round off your answer into three decimal places. (SHOW YOUR SOLUTION) 1. The mean of the masses of random samples of 21 blocks is 24 kg with a standard deviation of 1.50 kg. Determine a 90% confidence interval for estimating the mean mass of the population. 2. A random sample of 15 students was selected from a population size of 100 (normal) in a certain dormitory. The mean of weekly expenditures of the sample students is P400 with P17.50 standard deviations. Construct a 95% confidence interval for the average amount of expenditure of the resident in the dormitory.

I need the answers step by step

4. A new method for cholesterol utilizing 4 - aminoantipyrine was evaluated in the laboratory. The procedure was run in on 20 separate days. The following values are given: Mean = 150 mg/dl Sum of the squared difference from the mean is 3600 Calculate the SD.

1. A recent study of 22 motorists showed that they spent an average of P750 per week. The standard deviation of the sample was P90. Find the 99% confidence interval of the true mean. Solution: 2. A sample of 15 National Collegiate Athletics Association (NCAA) basketball players had an average height of 6 feet with a sample standard deviation of 0.80 foot. Find the 90% confidence interval of the true mean height of all players. Solution: