If a random sample of size 20 from a normal population with variance 225 has mean $\bar{x}=64.3$, then the 95% confidence interval for the population mean $\mu$ is (Given that $Z_{0.025}=1.96$).
Suppose that there are $K$ treatments and $n$ blocks in a randomized block design. In analysis of variance for this design, the error degrees of freedom is:
Thirty men and thirty women with knee pain were subjects in an experiment to determine the effectiveness of a new pain medication. Fifteen of the 30 men and 15 of the 30 women were chosen randomly to receive the new drug. The remaining 15 men and 15 women received a placebo. The decrease in pain was measured for each subject. Then the design of experiment is
A man purchased 5 toys at the rate of Rs. 200 each, 6 toys at the rate of Rs. 250 each and 9 toys at the rate of Rs. 300 each. The average cost of one toy is: