Prior to the 1999-2000 season, the National Basketball Association (NBA) made several rule changes designed to increase scoring. The average number of points scored in the previous season had been 183.2. A random sample of 25 games from the 1999-2000 season had a sample mean of 195.88 pts per game, a sample median of 196 pts per game and a sample standard deviation of 20.27 pts. The dot-plot of the data is shown below.

The researchers are trying to determine if the average number of points per game has increased from the previous season. Use this information to answer the following questions.

Flag this Question Question 1 3 pts

Describe the parameter in this study without referring to a value for the parameter.

Group of answer choices

Î¼

Î¼

is 183.2 points per game on average.

Î¼

Î¼

is the sample mean pts per game for the 1999-2000 basketball season.

Î¼

Î¼

is the population mean pts per game for the 1999-2000 basketball season.

Flag this Question Question 2 3 pts

State the null hypothesis in words only. Do not refer to a value for the parameter.

Group of answer choices
The population average points per game has changed from the previous season.

The population average points per game has increased from the previous season.

The population average points per game has not changed from the previous season.

The population average points per game is 183.2.

Flag this Question Question 3 3 pts

State the alternative hypothesis in words only. Do not refer to a value for the parameter.

Group of answer choices
The population average points per game has increased from the previous season.

The population average points per game has changed from the previous season.

The population average points per game is 183.2.

The population average points per game has not changed from the previous season.

Flag this Question Question 4 3 pts

State the null and alternative hypothesis using symbols and notation.

Group of answer choices
183.2″>

H

0

:

p

^

=

183.2

vs

H

A

:

p

^

>

183.2

H

0

:

p

^

=

183.2

vs

H

A

:

p

^

>

183.2

H

0

:

p

^

=

183.2

vs

H

A

:

p

^

â‰

183.2

H

0

:

p

^

=

183.2

vs

H

A

:

p

^

â‰

183.2

183.2″>

H

0

:

Î¼

=

183.2

vs

H

A

:

Î¼

>

183.2

H

0

:

Î¼

=

183.2

vs

H

A

:

Î¼

>

183.2

H

0

:

Î¼

=

183.2

vs

H

A

:

Î¼

â‰

183.2

H

0

:

Î¼

=

183.2

vs

H

A

:

Î¼

â‰

183.2

Flag this Question Question 5 3 pts

Are the validity conditions satisfied to use the theory-based approach for this hypothesis test? Explain clearly why or why not.

Group of answer choices
Yes, 20″>

n

=

25

>

20

n

=

25

>

20

and the sample data from the dot-plot is not too skewed.

Yes, n = 25 > 20.

Yes, the number of success and failures is greater than 10.

Flag this Question Question 6 12 pts

The statistical test ended up with a p-value

=

0.0031

. Using

Î±

=

0.01

, select all of the following statements that are correct. There may be none, one or more than one.

Group of answer choices
The statistical results are unlikely if the null is true.

The results are statistically significant.

We would not reject the null hypothesis.

There is little to no strength of evidence against the null.

The null is not a plausible explanation for what we observed.

Flag this Question Question 7 3 pts

The statistical test ended up with a standardized statistic of

t

=

3.01

. Interpret this value in terms of distance.

Group of answer choices
There is strong evidence against the null.

x

Â¯

x

Â¯

is 3.01 SD greater than

Î¼

Î¼

.

x

Â¯

x

Â¯

is 3.01 SD less than

Î¼

Î¼

.

p

^

p

^

is 3.01 SD greater than

Ï€

Ï€

.

Flag this Question Question 8 10 pts

Select all of the following statements that are true for this study. There may be more than one or none.

Group of answer choices
The researchers used an unbiased sampling method.

This sample of 25 games represents the population of all NBA games in the 1999-2000 season.

The study used convenience sampling to get the sample.

The results of this study only apply to the sample and can not be generalized to the population.

Flag this Question Question 9 4 pts

Calculate the 2SD CI using the formula

x

Â¯

Â±

2

â‹…

(

s

n

)

. Do not round any values until the final answer. Round the lower and upper bounds to 1 decimal place.

Enter the CI: ( , ).

Flag this Question Question 10 3 pts

Interpret the CI calculated in the previous question.

Group of answer choices
We are 90% confident that the interval contains

Î¼

Î¼

, the population mean points per game for the current 1999-2000 NBA season.

We are 99% confident that the interval contains

Î¼

Î¼

, the population mean points per game for the current 1999-2000 NBA season.

We are 95% confident that the interval contains

Î¼

Î¼

, the population mean points per game for the current 1999-2000 NBA season.