An automotive part must be machined to close tolerances to be acceptable to customers. production specifications call for a maximum variance in the lengths of the parts of .0004. suppose the sample variance for 30 parts turns out to be s 2 = .0005. use = .05 to test whether the population variance specification is being violated.
state the null and alternative hypotheses.
h0 : σ2
ha : σ2
calculate the value of the test statistic (to 2 decimals).
the p-value is what is your conclusion?

Since 36.25 is less than 42.56, we do not reject H_o.

Step-by-step explanation:

Given n=30, s^2=0.0005

The test hypothesis is

H_o:σ^2=0.0004

Ha:σ^2 not equal to 0.0004

The test statistic is

χ^2= (n-1)×s^2/σ^2 = (30-1)*0.0005/0.0004=36.25

Given a=0.05, the critical value is χ-square with 0.95, d_f=n-1=29= 42.56 (check χ-square table)

Since 36.25 is less than 42.56, we do not reject H_o.

So we can conclude that the population variance specification is being violated.

b. 24 mm

step-by-step explanation:

use the pythagorean theorem.

a^2 + b^2 = c^2

a^2 + 7^2 = 25^2

a^2 + 49 = 625

a^2 = 576

a = 24

answer: b. 24 mm

answer: the correct one is a

step-by-step explanation: