Statistics Solutions

Solution: A random sample of 22 bolts widely used in the construction industry yielded the following information; ∑limits_i=1^nX_i=231, ∑limits_i=1^nX_i^2=2428.6,

Question: A random sample of 22 bolts widely used in the construction industry yielded the following information;

\[\sum\limits_{i=1}^{n}{{{X}_{i}}=231,\,\,\,\sum\limits_{i=1}^{n}{X_{i}^{2}}=2428.6,\,\,\,\,n=22}\]

where the random variable X represents the length of the bolt in centimeters.

  1. Find the 99% confidence limits of (i) the true mean and (ii) the true standard deviation of the probability distribution of X. Assume that X is a normally distributed random variable.
  2. The production engineer claims that the mean length of this type of bolt is 10.7 centimeters. Do the results obtained from the sample support the production engineer’s claim? Let \(\alpha =0.05\).

(c) The production engineer also claims that the standard deviation of the length of this type of bolt is 0.25cm. Do the results obtained from the sample support this claim? Use \(\alpha =0.05\).

Price: $2.99
Solution: The downloadable solution consists of 3 pages
Deliverable: Word Document


∴ Other downloads you may be interested in ∴

log in to your account

Forgot password?
Don't have a membership account?
REGISTER

reset password

Back to
log in

sign up

Back to
log in