Variant 8

Date: 2015-10-07; view: 421.

The size of items which were made on a factory is =45millimeters. We tested 18 items that were selected randomly (data are presented in a table). Using confidence level 0.05, verify if there is a common deviation in a selected item set.

A laboratory made an analysis of 8 samples using 2 methods. The results are shown in the table.

Using confidence level 0.01 verify, if the measurements results differ significantly (we suppose them to be distributed normally)

After 100 independent tests we found relative frequency 0.14. Using confidence level 0.05 verify a hypothesis: p=0.15, when a competing hypothesis is p<0.15.

Using three independent samples with volumes 19,23,35 items correspondingly selected from normal universal sets we found corrected sampling variances: 4.2, 3.8, 6.3. Using a confidence level 0.05 verify a null hypothesis on homogeneity of variance

X is normally distributed. Sample volume n=35, sampling average =5, the corrected standard deviation s=0.2. Estimate the unknown mean using confident intervals. Reliability g=0.95.