22/24 that's 92%
RETAKE
22 questions were answered correctly.
2 questions were answered incorrectly.
1
A researcher has a table of data with 5 column variables and
4 row variables.
The value for the degrees of freedom in order to calculate the
!statistic is __________.
¥ (
12(
¥ (
4(
¥ (
20(
¥ (
19(
RATIONALE
Recall to get the degrees of freedom we use df = (r-1)(c-1) where
c and r are the number of rows and columns.! This means df =
(5-1)(4-1) = 4*3 =12.
CONCEPT
Chi-Square Test for Association and Independence
,Report an issue with this question
2
What value of z* should be used to construct an 88%
conÞdence interval of a population mean? Answer choices are
rounded to the thousandths place.
¥ (
1.555(
, ¥ (
1.645(
¥ (
1.220(
¥ (
1.175(
RATIONALE
Using the z-chart to construct an 88% CI, this means that there is
6% for each tail.! The lower tail would be at 0.06 and the upper
tail would be at (1 - 0.06) or 0.94.! The closest to 0.94 on the z-
table is between 0.9394 and 0.9406.!!
0.9394 corresponds with a z-score of 1.55.(
0.9406 corresponds with a z-score of 1.56.
Taking the average of these two scores, we get a z-score of
1.555.
CONCEPT
ConÞdence Intervals
Report an issue with this question
3
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.
!
Select the 95% conÞdence interval for Mrs. Pellegrin's set of
data.!
, ¥ (
9.34 to 10.44(
¥ (
9.48 to 10.44(
¥ (
9.4 to 10.52(
¥ (
9.53 to 10.39(
RATIONALE
In order to get the 95% CI , we Þrst need to Þnd the critical t-
score. Using a t-table, we need to Þnd (n-1) degrees of freedom,
or (5-1) = 4 df and the corresponding CI
Using the 95% CI in the bottom row and 4 df on the far left
column, we get a t-critical score of 2.776.
We also need to calculate the mean:(
(
So we use the formula to Þnd the conÞdence interval:
The lower bound is:
9.96 -0.56 = 9.40
The upper bound is:
9.96+0.56 = 10.52
CONCEPT
ConÞdence Intervals Using the T-Distribution
Report an issue with this question
4
RETAKE
22 questions were answered correctly.
2 questions were answered incorrectly.
1
A researcher has a table of data with 5 column variables and
4 row variables.
The value for the degrees of freedom in order to calculate the
!statistic is __________.
¥ (
12(
¥ (
4(
¥ (
20(
¥ (
19(
RATIONALE
Recall to get the degrees of freedom we use df = (r-1)(c-1) where
c and r are the number of rows and columns.! This means df =
(5-1)(4-1) = 4*3 =12.
CONCEPT
Chi-Square Test for Association and Independence
,Report an issue with this question
2
What value of z* should be used to construct an 88%
conÞdence interval of a population mean? Answer choices are
rounded to the thousandths place.
¥ (
1.555(
, ¥ (
1.645(
¥ (
1.220(
¥ (
1.175(
RATIONALE
Using the z-chart to construct an 88% CI, this means that there is
6% for each tail.! The lower tail would be at 0.06 and the upper
tail would be at (1 - 0.06) or 0.94.! The closest to 0.94 on the z-
table is between 0.9394 and 0.9406.!!
0.9394 corresponds with a z-score of 1.55.(
0.9406 corresponds with a z-score of 1.56.
Taking the average of these two scores, we get a z-score of
1.555.
CONCEPT
ConÞdence Intervals
Report an issue with this question
3
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.
!
Select the 95% conÞdence interval for Mrs. Pellegrin's set of
data.!
, ¥ (
9.34 to 10.44(
¥ (
9.48 to 10.44(
¥ (
9.4 to 10.52(
¥ (
9.53 to 10.39(
RATIONALE
In order to get the 95% CI , we Þrst need to Þnd the critical t-
score. Using a t-table, we need to Þnd (n-1) degrees of freedom,
or (5-1) = 4 df and the corresponding CI
Using the 95% CI in the bottom row and 4 df on the far left
column, we get a t-critical score of 2.776.
We also need to calculate the mean:(
(
So we use the formula to Þnd the conÞdence interval:
The lower bound is:
9.96 -0.56 = 9.40
The upper bound is:
9.96+0.56 = 10.52
CONCEPT
ConÞdence Intervals Using the T-Distribution
Report an issue with this question
4
