Question 1

Use a scatter plot to determine the relationship between the x values and the y values.

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Question 2

Use the equation of the regression line to predict

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Question 3

Determine whether a correlation coefficient of r = 0.091 is significant at the 5% level for a sample
Size of 120.

Accepted Answer

To determine the significance of the correlation coefficient, we need to compare it with the critical value of the correlation coefficient at the 5% significance level for a sample size of 120. Using a table or calculator, we find that the critical value is approximately ±0.196. Since the calculated correlation coefficient (r = 0.091) is less than the critical value, we can conclude that it is not significant at the 5% level. Therefore, the answer is B. To determine if a correlation coefficient is significant at a certain level, we need to use a significance test. The null hypothesis for a significance test of a correlation coefficient is that there is no relationship between the two variables in the population (i.e., the true correlation coefficient is zero).

To conduct the significance test, we need to calculate the t-statistic using the following formula:

t = r * sqrt(n-2) / sqrt(1-r^2)

where r is the sample correlation coefficient, n is the sample size, and sqrt() means "take the square root of."

In this case, r = 0.091 and n = 120, so

t = 0.091 * sqrt(120-2) / sqrt(1-0.091^2) = 0.958

To determine if this t-value is significant at the 5% level, we need to compare it to the critical t-value with 118 degrees of freedom (df = n-2) and a significance level of 0.05. Using a t-table or a calculator, we find that the critical t-value is 1.980.

Since our calculated t-value (0.958) is less than the critical t-value (1.980), we fail to reject the null hypothesis. That means we do not have enough evidence to say that there is a significant correlation between the two variables in the population.

Therefore, the correct answer is B: r is not significant at 5%.

Question 4

Draw a scatter plot and describe the relationship.

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Question 5

Find the equation of the regression line.

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Question 6

Find the value for r and test the significance of r at the 5% level and at the 1% level.

Accepted Answer

Since the value of r is not given in the question, it cannot be determined directly. However, based on the answer choices, we can see that options A and C both give a value of r = 0.998, while options B and D give a value of r = 0.995. 
Now, according to the options, r is significant at the 5% level and the 1% level for option A, which means that there is strong evidence to suggest that the correlation coefficient is not zero. This is also supported by the high value of r (=0.998) which indicates a very strong positive correlation between the two variables. 
On the other hand, option B suggests that r is significant only at the 5% level, but not at the 1% level. This means that while there is some evidence to suggest that the correlation coefficient is not zero, it is not as strong as in option A. 
Option C is similar to option A, as it also gives a value of r = 0.998 and suggests that r is significant at the 5% level, but not at the 1% level. This means that while the evidence is strong, it is not strong enough to reject the null hypothesis at the 1% level. 
Lastly, option D suggests that r is not significant at either the 5% level or the 1% level. This means that there is no evidence to suggest that the correlation coefficient is not zero.

Therefore, the best choice is A as it gives a strong value for r and suggests strong evidence to support the correlation at both the 5% and 1% levels.

Question 7

Find the equation of the regression line and predict y when x = 19.

Accepted Answer

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Question 8

Find the equation of the regression line.

Accepted Answer

The answer of Find the equation of the regression line....

Question 9

Find the value for the correlation coefficient r.

Accepted Answer

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Question 10

Find the equation of the regression line.

Accepted Answer

The answer of Find the equation of the regression line....

Question 11

Use a scatter plot to determine the relationship between the x values and the y values.

Accepted Answer

The answer of Use a scatter plot to determine the...

Question 12

Find the value for the correlation coefficient r.

Accepted Answer

The answer of Find the value for the correlation coefficient...

Question 13

Find the value for r and test the significance of r at the 5% level.

Accepted Answer

The answer of Find the value for r and test...

Question 14

Find the equation of the regression line and predict y when

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The answer of Find the equation of the regression line...

Question 15

Find the value for the correlation coefficient r.

Accepted Answer

The answer of Find the value for the correlation coefficient...

Question 16

Match each value of r with the appropriate graph.

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The answer of Match each value of r with the...

Question 17

Find the value for the correlation coefficient r.

Accepted Answer

Without additional information or data, it is impossible to calculate the correlation coefficient (r). The value given in the question (11ebb939_4a75_552c_9e6c_ab9068fd38b4_TB8446_00) appears to be a code or identifier, and not a numerical value for r. Based on the given code, we cannot calculate the correlation coefficient r. More information is needed or this is an error in the question.

Question 18

Find the equation of the regression line.

Accepted Answer

The answer of Find the equation of the regression line....

Question 19

A data set of size 21 has correlation coefficient of r = 0.476. Test the significance of r at the 5%
Level and at the 1% level.

Accepted Answer

To test the significance of the correlation coefficient at the 5% and 1% levels, we need to perform a hypothesis test. Null hypothesis: The population correlation coefficient is zero (i.e., there is no significant correlation). Alternative hypothesis: The population correlation coefficient is non-zero (i.e., there is a significant correlation). Using a two-tailed test, we can use the t-distribution with n-2 degrees of freedom to obtain the critical values. For a 5% significance level, the critical value is ±2.085. For a 1% significance level, the critical value is ±2.831. Next, we calculate the t-statistic for the sample correlation coefficient using the formula: t = r * sqrt(n-2) / sqrt(1-r^2) Plugging in the values, we get: t = 0.476 * sqrt(21-2) / sqrt(1-0.476^2) = 2.189 Since t > 2.085, we can reject the null hypothesis at the 5% level and conclude that there is a significant correlation. However, since t < 2.831, we cannot reject the null hypothesis at the 1% level. Therefore, the answer is A, r is significant at 5%, but not at 1%. To test the significance of r, we use the t-test for correlation coefficient. For n=21, r=0.476, and a two-tailed test at the 5% level, the critical t-value is ±2.085 (from a t-table or calculator). The calculated t-value is t=2.168 (using the formula t=r√(n-2)/√(1-r^2)), which is greater than the critical t-value. Since 2.168 > 2.085, we reject the null hypothesis and conclude that r is significant at the 5% level. For a two-tailed test at the 1% level, the critical t-value is ±2.831. Since 2.168 < 2.831, we fail to reject the null hypothesis and conclude that r is not significant at the 1% level.

Question 20

Use the equation of the regression line to predict y when

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Quiz 11: Statistics

Use a scatter plot to determine the relationship between the x values and the y values.

Use the equation of the regression line to predict

Determine whether a correlation coefficient of r = 0.091 is significant at the 5% level for a sample Size of 120.

Draw a scatter plot and describe the relationship.

Find the equation of the regression line.

Find the value for r and test the significance of r at the 5% level and at the 1% level.

Find the equation of the regression line and predict y when x = 19.

Find the equation of the regression line.

Find the value for the correlation coefficient r.

Find the equation of the regression line.

Use a scatter plot to determine the relationship between the x values and the y values.

Find the value for the correlation coefficient r.

Find the value for r and test the significance of r at the 5% level.

Find the equation of the regression line and predict y when

Find the value for the correlation coefficient r.

Match each value of r with the appropriate graph.

Find the value for the correlation coefficient r.

Find the equation of the regression line.

A data set of size 21 has correlation coefficient of r = 0.476. Test the significance of r at the 5% Level and at the 1% level.

Use the equation of the regression line to predict y when