the precision of equipment and instruments is measured by the variability of their operation under repeated conditions. the output from an automatic lathe producing diameter in millimeters of a part gave the following readings for a random sample of size 10:

10.3 9.7 9.6 9.5 9.9

10.2 9.8 10.1 10.2 9.8

find a 90% confidence interval for both the variance and standard deviation of the diameters.

choice:

variance:

A.(0.0107, 0.5067)

B.(0.0207, 0.4067)

C.(0.0307, 0.3067)

D.(0.0407, 0.2067)

standard deviation:

A.(0.2017, 0.4546)

B.(0.3017, 0.5546)

C.(0.4017, 0.6546)

D.(0.5017, 0.7546)

then test the null hypothesis that the variance of the diameters does not exceed .05mm²

use a significance level of .10

choices: true or false