MGMT305-Lec7

# Parincisamanufacturerofgolfequipmentparhasdevelopeda

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: normal distributions 2 2 σ = σ2 = σ 2 Variances are equal: 1 11 Then σ x1 − x2 = σ 2 ( + ) n1 n2 Interval Estimate with σ1 and σ2 unknown and small­ sample case: x1 − x2 ± tα / 2 sx1 − x2 sx1 − x2 11 = s( + ) n1 n2 2 NOTE: Use t distribution 2 2 ( n1 − 1) s1 + ( n2 − 1) s2 s= n1 + n2 − 2 2 Slide 8 Interval Estimate of µ 1 ­ µ 2 Example 1: Par, Inc. Par, Inc. is a manufacturer of golf equipment. Par has developed a new golf ball that has been designed to provide “extra distance.” In a test of driving distance using a mechanical driving device, a sample of Par golf balls was compared with a sample of golf balls made by Rap, Ltd., a competitor. The sample data is given below. Sample #1 Par, Inc. Par, Sample #2 Sample Rap, Ltd. Rap, Sample Size n1 = 120 balls n2 = 80 balls Mean Standard Deviation Standard = 235 yards x1 = 15 yards s1 = 218 yards x22= 20 yards s Slide 9 Example 1: Par, Inc. s Point Estimate of the Difference Between Two Population Means µ1 = mean distance for the population of Par, Inc. golf balls µ2 = mean distance for the population of Rap, Ltd. golf balls (a) What is the point estimate of µ1 ­ µ2? Slide 10 Example 1: Par, Inc. (b) Compute the 95% Confidence Interval Estimate of the Difference Between Two Population Means. s We are 95% confident that the difference between the mean driving distances of Par, Inc. balls and Rap, Ltd. balls lies in the interval of Slide 11 Example 2 : Specific Motors Specific Motors of Detroit has developed a new automobile known as the M car. 12 M cars and 8 J cars (from Japan) were road tested to compare miles­per­ gallon (mpg) performance. The sample statistics are: Sample Size Mean Standard Deviation Sample #1 Sample #2 M Cars J Cars n1 = 12 cars n2 = 8 cars x1 x2 = 29.8 mpg = 27.3 mpg s1 = 2.56 mpg s2 = 1.81 mpg Slide 12 Example 2: Specific Motors s Point Estimate of the Difference Between Two Population Means µ1 = mean miles­per­gallon for the population of M cars µ2 = mean miles­per­gallon for the population of J cars (a) What is the point estimat...
View Full Document

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern