From extensive records, it is known that the duration of treating a disease by a standard therapy has a mean of 15 days with a standard deviation of 3 days. It is claimed that a new therapy can reduce the treatment time. To test this claim, the new therapy is tried on 70
patients, and their average treatment time is calculated to be 14.6 days.
Calculate the standard normal distribution value for the 97% confidence level [3]
Test the claim supported at a 97% confidence level [9]
Indicate the P-value for this test in (c). [4]
We want to estimate the population mean within 5, with a 99% level of confidence. The population standard deviation is estimated to be
2. How large a sample is required?