2. 3 7. 10 11 12 13 Hospital Noise Levels Noise levels at varlous area urban hospitals were measured in decibels. The mean noise level in 167 ward areas was 59.5 decibels, and the population standard deviation is 5.4. Find the 99% confidence Interval of the true mean. Round your answers to at least one decimal place. db

mg mg Calcium levels in people are normally distributed with a mean of 9.5 and a standard deviation of 0.3 dL dL Individuals with calcium levels in the bottom 15% of the population are considered to have low calcium levels. Find the calcium level that is the borderline between low calcium levels and those not considered low. Carry your intermediate computations to at least four decimal places. Round your answer to one decimal place. mg dL X

You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately o = 74.3. You would like to be 98% confident that your estimate is within 3 of the true population mean. How large of a sample size is required? Round up to nearest whole number. n =

Only answer part B. Obviously part a is answered

This data is from a sample. Calculate the mean, standard deviation, and coefficient of variation. 18.1 19.6 13.2 31.4 14.1 45 10.2 35.4 36.5 Please show the following answers to 2 decimal places. Mean = Standard Deviation= % (Please enter a whole number.) %3D Coefficient of Variation