STATISTICS MISC
FINAL MILESTONE
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Sukie interviewed 125 employees at her company and discovered that 21
... [Show More] of them planned to take an extended vacation next year. She finds that the proportion of people taking extended vacations nationally is 15%.
The z statistic for this data is .
-0.56
-0.45
0.56
0.45
RATIONALE
To make things a little easier, let's first note the denominator We can now note that
Finally, subbing all in we find
CONCEPT
Z-Test for Population Proportions 2
Jesse takes two data points from the weight and feed cost data set to calculate a slope, or average rate of change. A rat weighs 3.5 pounds and costs $4.50 per week to feed, while a Beagle weighs 30 pounds and costs $9.20 per week to feed.
Using weight as the explanatory variable, what is the slope of the line between these two points? Answer choices are rounded to the nearest hundredth.
$0.31 / lb.
$1.60 / lb.
$5.64 / lb.
$0.18 / lb.
RATIONALE
In order to get slope, we can use the formula: .
Using the information provided, the two points are: (3.5 lb., $4.50) and (30 lb., $9.20). We can note that:
CONCEPT
Linear Equation Algebra Review 3
A research team conducts a survey to determine the area of land used for farming in Iowa. The team randomly selects house addresses and sends the survey by mail.
Which type of sampling method is the research team using?
Simple random sampling
Systematic random sampling
Multi-stage sampling
Cluster sampling
RATIONALE
By choosing randomly from the house addresses all households should have an equal chance of being chosen. This would make it a simple random sample.
CONCEPT
Simple Random and Systematic Random Sampling 4
Katherine, Jonathan, and Ryan went bowling. Afterwards, two of them decided to make bar graphs to plot their scores.
Who made Graph 2, and why?
Jonathan, because he wanted to make the scores appear reasonably close.
Katherine, because she wanted to make the scores appear reasonably close.
Katherine, because she wanted to accurately show each person's score.
Jonathan, because he wanted to make the scores appear very different.
RATIONALE
Since there was a competition, the person who most likely made this graph would want to represent themselves favorably. Jonathan appears to be the lowest scorer in both graphs, but in graph 2 it looks like he scored about the same as Ryan and Katherine. Jonathan probably made this graph to make it appear as if his score was close to the others.
CONCEPT
Misleading Graphical Displays 5
Which of the following is an example of a false positive?
Test results indicate that a patient has cancer when, in fact, he does not.
Test results indicate that a patient does not have cancer when, in fact, he does.
Test results confirm that a patient does not have cancer.
Test results confirm that a patient has cancer.
RATIONALE
Since the test results indicate positively that the patient has cancer, when in fact cancer is not present, this is a false positive.
CONCEPT
False Positives/False Negatives 6
Jessica uses a poorly calibrated stopwatch to note the finish time of a relay race. She noted the time as 125 seconds, whereas the actual time taken was 120 seconds.
The percent error in Jessica's calculation is .
-4.2%
4.0%
4.2%
-4.0%
RATIONALE
Recall that the percent error is equivalent to the absolute difference divided by the actual value.
If the actual measure is 120 seconds and the observed measure is 125 seconds, then the absolute difference is:
So we calculate the percentage error to be: [Show Less]