In a random sample of 400 students and 600 graduates who studies a given pre- requisite course upon entry into university, 100 students and 300 graduates indicated that they found it helpful. Construct a 99% confidence interval for the difference in proportions of all students and all graduates who took a given pre-requisite course and found it helpful.
Q4
In a random sample of 400 students and 600 graduates who studies a given pre-
requisite course upon entry into university, 100 students and 300 graduates indicated
that they found it helpful. Construct a 99% confidence interval for the difference in
proportions of all students and all graduates who took a given pre-requisite course and
found it helpful.
b) The standard deviation of the running time of a sample of 200 fuses was found to be
100 hours. Find a 99% confidence interval for the standard deviation of all such fuses.
c) Two samples, sample one of size 16 and sample two of size 10, respectively, are drawn
at random from two populations that are
found to be 24 and 18, respectively, find:
i. 98% confidence interval for the ratio of the variances.
ii. 90% confidence interval for the ratio of the variances.
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