In: Statistics and Probability
Use the given information to find the number of degrees of freedom, the critical values chi Subscript Upper L Superscript 2 and chi Subscript Upper R Superscript 2, and the confidence interval estimate of sigma. It is reasonable to assume that a simple random sample has been selected from a population with a normal distribution. Platelet Counts of Women 90% confidence; nequals24, sequals65.4.
Solution :
Given that,
s = 65.4
2R = 2/2,df = 35.173
2L = 21 - /2,df = 13.091
The 90% confidence interval for is,
(n - 1)s2 / 2/2 < < (n - 1)s2 / 21 - /2
23 * 65.6 2 / 35.173 < < 23 * 65.6 2 / 13.091
52.8859 < < 86.6889
(52.8859 , 86.6889)