Question

- The following matrix displays the bivariate correlations between family size (X), weekly grocery bill (Y), and income (Z) for a random sample of 50 families.

X Y Z

X 1.00 .60 .20

Y .60 1.00 .30

Z .20 .30 1.00

- First, list the values of the 3 unique correlations, identifying the two variables in each correlation in some way.
- Which of the correlations is statistically significant at the .05 level? Be sure to record the information on which you base these conclusions. (This implies you will need to perform a hypothesis test assessing whether each correlation is large enough to suggest that a real association exists in the population from which the sample was drawn.)

Answer #1

The following matrix displays the bivariate correlations
between family size (X), weekly grocery bill (Y), and income (Z)
for a random sample of 50 families.
X
Y
Z
X
1.00
.60 .20
Y
.60
1.00 .30
Z
.20
.30 1.00
First, list the values of the 3 unique correlations,
identifying the two variables in each correlation in some way.
(rxy = ?; rxz = ? ryz = ?)
Which of the correlations is statistically significant at the
.05 level?...

The table below shows a set of bivariate data: X and Y.
Calculate the covariance and correlation coefficients by
completing the below table, assuming sample data. Show all
workings. (Note: You can calculate the mean and standard deviation
of X & Y with Excel or your calculator; no working for their
calculation is required.)
X
Y
(X - X bar)
(Y - Y bar)
(X - X bar)(Y - Y bar)
5
5
-0.2
-0.6
0.12
2
3
-3.2
-2.6...

1. For a pair of sample x- and y-values, what is the difference
between the observed value of y and the predicted value of y? a) An
outlier b) The explanatory variable c) A residual d) The response
variable
2. Which of the following statements is false:
a) The correlation coefficient is unitless. b) A correlation
coefficient of 0.62 suggests a stronger correlation than a
correlation coefficient of -0.82. c) The correlation coefficient,
r, is always between -1 and 1....

Bivariate Data & Probability
After completing the calculation by hand in Q1 you can use
Excel to check your answers before submitting. Q2 assesses your
general understanding of probability and linear associations using
Excel to analyse a large dataset.
Question 1
Covariance and Correlation
The table below shows a set of sample bivariate data. Calculate
the covariance and correlation coefficient by completing the below
table. Show all working.
X
Y
(X - )
(Y - )
(X - )(Y -...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 4 minutes ago

asked 25 minutes ago

asked 31 minutes ago

asked 31 minutes ago

asked 35 minutes ago

asked 36 minutes ago

asked 39 minutes ago

asked 40 minutes ago

asked 42 minutes ago

asked 43 minutes ago

asked 43 minutes ago

asked 46 minutes ago