Tutorial 8

Tutorial 8

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: e the level of significance. (There are z and z2 in p0 (1 p0 ) / n the following table because the central limit theorem is applied.) Test H0 H1 Lefttailed p p0 or p p0 p p0 Righttailed p p0 or p p0 p p 0 Twotailed p p0 Reject H0 if and only if p p0 2 p p0 ˆ z p0 (1 p0 ) / n p p0 ˆ z p0 (1 p0 ) / n p p0 ˆ p0 (1 p0 ) / n z2 Questions I. Inference about a Population Mean when variance is known 1. A car has an average fuel consumption of 33 mpg (with σ = 5.7). We took the new model of the car out for 35 tests and collected the following data, x = 34.8 mpg. Does this new model have better fuel consumption than the original ¯ one? Assume the new model has the same σ , do a hypothesis test at 5% significance level. 2. A manufacturer has produced a large batch of fan-belts. From past experience he knows that his machine capability is σ = 0.7 cm which represents the standard deviation of fan-belt lengths in any large batch produced. To estimate the mean length (µ cm) of the batch, the manufacturer randomly selected 20 items and obtained these measurements (in cm): 52.5, 53.0, 52.3, 52.4, 52.7, 51.7, 52.1, 52.8, 53.1, 54.0, 52.9, 52.3, 51.6, 52.7, 52.6, 53.0, 52.3, 52.1, 51.7, 53.0 (a) Determine a 90% confidence interval for µ. (b) Test the null hypothesis H0 : µ = 52.0 versus the alternative H0 : µ ...
View Full Document

This note was uploaded on 08/26/2013 for the course STAT 0302 taught by Professor Guo during the Spring '12 term at HKU.

Ask a homework question - tutors are online