Statistics Fundamentals Unit 5 Milestone
You passed this Milestone
20 questions were answered correctly.
4 questions were answered incorrectly.
1
Mrs. Pellegrin has weighed 5 packages of cheese and recorded the weights
as 10.2 oz, 10.5 oz, 9.3 oz, 9.8 oz, and 10.0 oz. She calculated the standard
deviation to be 0.45 oz.
The cheese factory lists the package weight at 10 oz.
The t-statistic for a two-sided test would be __________.
+0.20
-0.20
-0.40
+0.40
RATIONALE
Using the information given, we need to find the sample mean:
We now know the following information:
Let's plug in the values into the formula:
CONCEPT
T-Tests
2
, A market research company conducted a survey to find the level of affluence
in a city. They defined the category "affluence" for males earning $100,000
or more annually and for females earning $80,000 or more annually. Out of
267 persons who replied to their survey, 32 are listed under this category.
What is the standard error of the sample proportion? Answer
choices are rounded to the hundredths place.
0.32
0.02
1.96
0.20
RATIONALE
We can note the SE of the proportion is .
If we note that , which means .
So if we take all this information we can note SE = .
CONCEPT
Calculating Standard Error of a Sample Proportion
3
Sukie interviewed 125 employees at her company and discovered that 21 of
them planned to take an extended vacation next year.
What is the 95% confidence interval for this population proportion?
Answer choices are rounded to the hundredths place.
0.11 to 0.16
0.16 to 0.17
0.11 to 0.21
, 0.10 to 0.23
RATIONALE
In order to get the CI we want to use the following form.
First, we must determine the corresponding z*score for 95% Confidence Interval.
Remember, this means that we have 5% for the tails, meaning 5%, or 0.025, for each
tail. Using a z-table, we can find the upper z-score by finding (1 - 0.025) or 0.975 in the
table.
This corresponding z-score is at 1.96.
We can know
So putting it all together:
The lower bound is:
0.168-0.065 =0.103 or 0.10
The upper bound is:
0.168+0.065 =0.233 or 0.23
CONCEPT
Confidence Interval for Population Proportion
4
For a left-tailed test, the critical value of z so that a hypothesis test
would reject the null hypothesis at 10% significance level would be
__________. Answer choices are rounded to the hundredths place.
-2.33
-1.03
-1.65
-1.28
RATIONALE
You passed this Milestone
20 questions were answered correctly.
4 questions were answered incorrectly.
1
Mrs. Pellegrin has weighed 5 packages of cheese and recorded the weights
as 10.2 oz, 10.5 oz, 9.3 oz, 9.8 oz, and 10.0 oz. She calculated the standard
deviation to be 0.45 oz.
The cheese factory lists the package weight at 10 oz.
The t-statistic for a two-sided test would be __________.
+0.20
-0.20
-0.40
+0.40
RATIONALE
Using the information given, we need to find the sample mean:
We now know the following information:
Let's plug in the values into the formula:
CONCEPT
T-Tests
2
, A market research company conducted a survey to find the level of affluence
in a city. They defined the category "affluence" for males earning $100,000
or more annually and for females earning $80,000 or more annually. Out of
267 persons who replied to their survey, 32 are listed under this category.
What is the standard error of the sample proportion? Answer
choices are rounded to the hundredths place.
0.32
0.02
1.96
0.20
RATIONALE
We can note the SE of the proportion is .
If we note that , which means .
So if we take all this information we can note SE = .
CONCEPT
Calculating Standard Error of a Sample Proportion
3
Sukie interviewed 125 employees at her company and discovered that 21 of
them planned to take an extended vacation next year.
What is the 95% confidence interval for this population proportion?
Answer choices are rounded to the hundredths place.
0.11 to 0.16
0.16 to 0.17
0.11 to 0.21
, 0.10 to 0.23
RATIONALE
In order to get the CI we want to use the following form.
First, we must determine the corresponding z*score for 95% Confidence Interval.
Remember, this means that we have 5% for the tails, meaning 5%, or 0.025, for each
tail. Using a z-table, we can find the upper z-score by finding (1 - 0.025) or 0.975 in the
table.
This corresponding z-score is at 1.96.
We can know
So putting it all together:
The lower bound is:
0.168-0.065 =0.103 or 0.10
The upper bound is:
0.168+0.065 =0.233 or 0.23
CONCEPT
Confidence Interval for Population Proportion
4
For a left-tailed test, the critical value of z so that a hypothesis test
would reject the null hypothesis at 10% significance level would be
__________. Answer choices are rounded to the hundredths place.
-2.33
-1.03
-1.65
-1.28
RATIONALE
