Question

Answers to the following questions should be calculated in Matlab and given to 4 decimal places. Be careful not to introduce errors by rounding in any intermediate calculations as this may lead to an incorrect final answer.

A confidence interval is desired for the true average load loss μ (watts) for a certain type of induction motor when the line current is held at 10 amps for a speed of 1500 rpm.

A random sample of 48 motors were tested and the sample mean load loss was found to be 56.1 and the sample standard deviation was 2.5.

(c) Find the critical value t∗ required for a 95\% confidence interval

d) Give a 95% confidence interval for μ.

Enter your answer using the syntax (lower, upper) for example (1.0001, 2.2222)

Answer 1