QUESTION 1:
Find a 95% Cl for the population mean concentration. Find a 95% Cl for the population mean concentration (include the lower and upper limit values of the 95% Cl).
QUESTION 2:
What is the best estimate of the 1971 incidence rate from these data? What is the best estimate of the 1971 incidence rate from these data?
QUESTION 3:
Provide a 95% Cl for the true incidence rate.
A comparison was made between the Michigan report and 1969 cancer-incidence rates from the Connecticut tumor registry, where the expected incidence rate, based on the age distribution of the Michigan nurses, was determined to be 402.8 per 100,000 persons-years.
Find the 95% CI for the true incidence rate (include the lower and upper limit values of the 95% CI). Use 4 decimals for your calculations.
QUESTION 4:
Assuming an underlying normal distribution, compute 95% Cls for the mean and variance of the latency times. Find the lower and upper limit values of the 95% Cl for the mean ___________?, _________?, and the variance _______, ______.
QUESTION 5:
Some physicians feel a mammogram is not cost-effective unless one can be reasonably certain (e.g. 95% certain) that the fals-positive rate is less than 10%. Can you address this issue based on the preceding data? Calculate the lower and upper limit 95% Cl values, using three decimals.
QUESTION 6:
If the central-limit theorem holds, then what percentage of t-values should exceed 2.776 in absolute value? What percentage of t-values should exceed 2.776 in absolute value?
QUESTION 7:
Suppose we want to choose a large enough sample so that the sample mean is within 1 unit of the population mean 99% of the time. What is the minimum sample size to achieve this goal? What is the minimum sample size to achieve this goal?
QUESTION 8:
What is the sensitivity of the test? What is the sensitivity of the test? (Use decimals and not percentage.)