AP Stats Unit 9

Joaquin believes that increasing his walking speed will increase his pulse rate. In an attempt to model this relationship, Joaquin records his pulse rate, in beats per minute (bpm), while walking at each of ten different speeds, in miles per hour (mph). A regression computer output is shown above. Provided that the assumptions for regression inference are satisfied, what can you conclude about the relationship between the walking speed and the pulse rate of Joaquin?

• Since the p-value is greater than any reasonable significance level, there is significant evidence of a linear relationship between the Joaquin’s walking speed and his pulse rate.

• Since the p-value is less than any reasonable significance level, there is insignificant evidence of a linear relationship between the Joaquin’s walking speed and his pulse rate

• Since the p-value is less than any reasonable significance level, there is significant evidence of a linear relationship between the Joaquin’s walking speed and his pulse rate.

• Since the p-value is less than any reasonable significance level, no linear relationship exists between the Joaquin’s walking speed and his pulse rate.

Chi-squared tests are invalid if:

• The calculated number is really large

• One of the expected values is less than 5

• One of the observed values is less than 5

• The calculated numbers is really small

Find the degrees of freedom.

• 4

• 5

• 6

• 7

Which test would you use to see if age is a factor choosing a person’s favorite fruit? 900 college students were surveyed and their favorite fruit recorded.

• Chi-square Goodness of Fit Test

• Correlation coefficient

• Chi-Square Test for Independence

• Chi-square test for correlation

Involves dividing the population into subgroups, you randomly select entire subgroups. What sampling technique is this?

• Simple Random Sample

• Snowball Sample

• Cluster Random Sample

• Stratified Random Sample

The school district is interested in finding out student and parent opinions about the dress code.  They obtain a list of students from each school in the district and put them in alphabetical order.  They then send a survey to every 25th student and their parents on the list.

• Simple Random Sampling

• Stratified Random Sampling

• Systematic Sampling

• Convenience Sampling

• A

• B

• C

• D

• E

The school district is interested in finding out student and parent opinions about the dress code. They obtain a list of students from each school in the district and put them in alphabetical order. They then send a survey to every 25th student and their parents on the list.

• Simple Random Sampling

• Stratified Random Sampling

• Systematic Sampling

• Convenience Sampling

What is the

χ² _calculated value for the following situation.

• 6.65

• 6.66

• 0.00991

• 1

What are the degrees of freedom for the following χ² test?

• 6

• 2

• 5

• 12