Quiz Part 2 Revised Name:
each of the following short answer questions:
1. How is a
linear relationship between two variables measured in statistics? Explain.
2. What is
the symbol for the sample correlation coefficient? The population correlation
3. What is
the range of values for the correlation coefficient?
4. What is
the general form for the regression line used in statistics?
5. What is
meant by the “line of best fit”?
6. When all
the points fall on the regression line, what is the value of the correlation
the differences between the explained variation and the unexplained
following problem (# 8 below) perform the following steps.
Problem: Forest Fires and Acres Burned SHOW YOUR WORK
environmentalist wants to determine the relationships between the numbers (in
thousands) of forest fires over the year and the number (in hundred thousands)
of acres burned. The data for 8 recent years are shown.
Fires x │ 72
69 58 47
84 62 57 45
Acres y │
19 26 51
15 30 15
the scatter plot for the variables.
b. Compute the value of the
correlation coefficient and identify the line of best fit (y’ = a + bx) with
the specific values for a and b from the problem below.
c. State the hypotheses.
d. Test the significance of the
correlation coefficient at = 0.05. Using Table I or
the P-value method.
e. Give a brief explanation of the type of relationship.
Assume all assumptions have been met.
f. Find y’ when x = 60 fires.