10.2 Means sd Unknown

# The sample statistics are m cars hypothesis tests n x

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

This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: nd 28 J cars (from Japan) were road tested to compare mpg performance. The sample statistics are: M Cars Hypothesis Tests n x s J Cars 24 28 29.8 27.3 2.56 1.81 Difference Between 2 Population Means parameter point estimate standard error DM–J = μM – μJ d x −J= 5 =M x 2 . s 2 s2 s = M + J =06 5 .2 d n n M J margin of error interval estimate tα 2 s 2 s22 1 + n n2 1 s2 s22 1 + nn 1 2 d ±tα 2 degrees of df = freedom (+ ) ( )+ ( ) s2 1 n1 s2 1 1 n1 − n1 1 2 s22 n2 2 s22 1 n2 − n2 1 2 Example Given these samples, what is the margin of error for 90% confidence of the difference between the 2 population means? Specific Motors of Detroit has developed a new automobile known as the M car. 24 M cars and 28 J cars (from Japan) were road tested to compare need the mpg performance. The sample degrees of statistics are: Hypothesis Tests freedom to use M the t- Cars J Cars n 24 28 distribution x s 29.8 2.56 27.3 1.81 Difference Between 2 Population Means parameter point estimate standard error DM–J = μM – μJ d x −J= 5 =M x 2 . s 2 s2 s = M + J =06 5 .2 d n n M J margin of error interval estimate tα 2 s 2 s22 1 + n n2 1 s2 s22 1 + nn 1 2 d ±tα 2 degrees of df = freedom (+ ) ( )+ ( ) s2 1 n1 s2 1 1 n1 − n1 1 2 s22 n2 2 s22 1 n2 − n2 1 2 Given these samples, what is the margin of error for 90% confidence of the difference between the 2 population means? Example Difference Between 2 Population Means Specific Motors of Detroit has developed a new automobile known as the M car. 24 M cars and 28 J cars (from Japan) were road tested to compare need the need the mpg performance. The sample degrees of statistics are: of degrees Hypothesis Tests freedom to use freedom to use M the t- Cars J Cars the t- 24 n distribution s 28+ s distribution (n n x 29.8 27.3 2 M df = s 2.56 = J M 1 nM 2 J parameter point estimate standard error ) 2 ( 1.81+ ( ) ) sM 2 −1 n M 2 sJ 2 1 n J −1 n J 2 (+) ( )+ ( ) 2.56 2 24 1 2.56 2 24 −1 24 1.812 28 2 = 40.58 ≈ 40 2 1 1.812 28 −1 28 2 DM–J = μM – μJ d x −J= 5 =M x 2 . s 2 s2 s = M + J =06 5 .2 d n n M J margin of error interval estimate tα 2 s 2 s22 1 + n n2 1 s2 s22 1 + nn 1 2 d ±tα 2 degrees of df = freedom (+ ) ( )+ ( ) s2 1 n1 s2 1 1 n1 − n1 1 2 s22 n2 2 s22 1 n2 − n2 1 2 Example Given these samples, what is the margin of error for 90% confidence of the difference between the 2 population means? Specific Motors of Detroit has developed a new automobile known as the M car. 24 M cars and 28 J cars (from Japan) s1 2 s2 2 tα 2 n1 + 2 were road testedn to compare mpg performance. The sample sM 2 sJ 2 = 10 2 statisticst.are: n M + n J Hypothesis Tests = t.M 2Cars 10 ⋅ 0 . 625 J Cars n = 1 . 684 ⋅ 0 .625 28 24 x = 1 . 053 29.8 27.3 s 2.56 1.81 Difference Between 2 Population Means DM–J = μM – μJ parameter point estimate standard error d x −J= 5 =M x 2 . s 2 s2 s = M + J =06 5 .2 d n n M J margin of error interval estimate degrees of df = freedom tα 2 s 2 s22 1 + n n2 1 s2 s22 1 + nn 1 2 d ±tα 2 ( + ) ≈40 ( )+ ( ) sM2 nM sM2 1 nM − nM 1 2 sJ 2 nJ 2 sJ 2 1 nJ − nJ 1 2 Example Given these samples, what is the...
View Full Document

## This document was uploaded on 03/05/2014.

Ask a homework question - tutors are online