PLEASE ANSWER THE FOLLOWING PLEASE TYPE THE ANSWER HERE

Part 1 (Solving Confidence Interval) - Answer the following: 1. A recent study involving 18 college students showed that the average time they spend studying during weekends (Sat & Sun) was 5.75 hours. Find the 90% confidence interval of the true mean if the standard deviation of the sample was 1 hour. [Delete this then place your answer inside this box] 2.~ Among the 1,000 sports enthusiasts who frequent local sports bars, 780 prefer basketball over football. Set up a 99% confidence interval estimate for the true proportion. [Delete this then place your answer inside this box] 3. A researcher wants to estimate the average age of Grab drivers in Manila. From past surveys, the standard deviation is known to be 4 years. A sample of 80 Grab drivers is selected, and the mean is found to be 26.3 years. Find the 90% confidence interval of the population mean. [Delete this then place your answer inside this box] 1. We want to estimate the proportion of students who shift to different courses. Suppose that we want to be at least 90% sure with margin of error at 0.06 proportion, how large a sample will we need? [Delete this then place your answer inside this box] 2. If we wish to estimate the monthly expenses of families in Barangay 826, how large a sample is necessary if we want a 95% confidence level and with a margin of error equal to 800 pesos. Use a standard deviation of 2,750 pesos which is from previous studies. [Delete this then place your answer inside this box] 3. We want to estimate the proportion of readers who still prefer "paper" books over "electronic" books (or e-books). Suppose that we want to be 99% sure with margin of error at 0.08 proportion, how large a sample will we need if we know that the true proportion is between 0.05 and 0.25