Credit-Quiz-Ch3-Key

# Credit-Quiz-Ch3-Key - Key to BUS-271 In-class Quiz over...

This preview shows pages 1–3. Sign up to view the full content.

1 Key to BUS-271 In-class Quiz over Chapter 3 2011-09-01 [Over 27 points] 305. [Ch. 3; 27 points] (Descriptive statistics) We want to examine whether there is any relationship between a student’s age and his or her height, using a subset of the data for this class: X = the student’s age (in years) Y = the student’s height (in inches) I x i y i --- --- ---- 1 41 60 2 32 64 3 27 67 4 24 71 5 19 72 6 21 74 7 20 78 First, calculate the following sums: a. [2 p.] 5 1 i i x 143 b. [2 p.] 5 1 i i y 334 c. [2 p.] X 26.29 d. [2 p.] Y 69.43 e. [2 p.] 7 3 () i i xX  -20.45 f. [2 p.] 7 3 ii i xy  7,995 g. [2 p.] 6 2 ( ) ( ) i x X y Y -79.23

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
2 Next, the following pre-calculated sums for the above data set are provided for your use: 2 2 2 5, 212.00 ( ) 0 ( ) 375.43 ( ) 0 ( ) 227.71 12,503.00 ( ) ( ) 271.86 i i i i i ii x xX yY xy x X y Y     Using this information, and considering our little data set a sample : h. [6 p.] Calculate the co-variance s xy and the standard deviations s x and s y : 2 2 375.43 7.91 16 () xx i n X x ss
This is the end of the preview. Sign up to access the rest of the document.

## This document was uploaded on 09/23/2011.

### Page1 / 3

Credit-Quiz-Ch3-Key - Key to BUS-271 In-class Quiz over...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online