Ap Stats Unit 7 Learning About the World Review Answers
Answers and Review for Multiple Pick Practice on Inference for Quantitative Data: Ways
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⛔Finish ⛔ Before you lot await at the answers make sure you gave this practice quiz a endeavor so you can assess your agreement of the concepts covered in Unit seven. Click here for the do questions: AP Statistics Unit of measurement 7 Multiple Pick Questions .
Facts about the test: The AP Statistics exam has twoscore multiple pick questions and y'all will be given 1 hour 30 minutes to complete the department. That means information technology should take y'all around eleven minutes to complete 5 questions.
Resources:
The following questions were not written past Higher Board and although they cover information outlined in the AP Statistics Form and Examination Clarification the formatting on the examination may exist different.
1. How do you lot calculate the degrees of liberty for a i sample t test?
A. n
B. n-1
C. northward/two
D. 2n
Respond: To find the degrees of freedom, subtract one from the sample size. Degrees of freedom refers to how many chosen for your sample are free to be whatsoever they please and withal get the given population mean. For case, if the population mean is ten and our sample size is five, the first 4 we choose for our sample can exist basically whatever they want. However, the last ane would be fixed (AKA not free) in order to get the hateful of x.
2. A matched pairs experiment would work best with a ___________ confidence interval.
A. ane Sample T
B. 2 Sample T
C. 1 Proportion T
D. 2 Sample Z
Answer: Since it is a matched pair experiment, every subject area received both treatments. Therefore, we can subtract the average for each bailiwick and it substantially becomes one sample using the differences. Since we are estimating a hateful, we use a t interval.
3. Which of the following is NOT a way to verify that our sampling distribution of our mean is approximately normal?
A. Sample plot shows no skewness or outliers.
B. Population is normally distributed
C. Sample size of at to the lowest degree 30
D. Sample mean of at least xxx
Answer: The size of our sample mean does non make up one's mind shape at all. However, sample size does (Central Limit Theorem) forth with a normal population or a fairly symmetric sample distribution.
📄 Written report AP Statistics, Unit of measurement seven.0: Unit 7 Overview
four. A study concludes by estimating the true mean weight of giraffes in Africa by giving a 95% confidence interval of (1600, 2000). Translate this confidence interval.
A. 95% of giraffes counterbalance between 1600 and 2000 pounds.
B. There is a 95% probability that a giraffe weighs between 1600 and 2000 pounds.
C. We are 95% confident that the true hateful weight of giraffes is between 1600 and 2000 pounds.
D. At that place is only a 5% chance of selecting a giraffe that weighs outside of 1600 and 2000 pounds.
Answer: The correct interpretation is more than so about the interval, not the population hateful. We are that sure that the confidence interval we take contains the true mean. This is a good template to larn and exist familiar with.
5. Which status would allow u.s. to use a z interval instead of a t interval to guess a population mean?
A. When the population standard deviation is known
B. When the sample size is at least 100
C. When we know the sample mean
D. When the sample is x% of our population
Respond: In the rare occasion that the population standard divergence is known, one can use a z interval instead of a t interval to estimate a population hateful. Still, this is pretty rare since this would usually mean you know the population mean (in which instance information technology would exist pointless to try to estimate something that y'all already know)
📄 Written report AP Statistics, Unit of measurement 7.0: Unit 7 Overview
6. What happens to the width of a confidence interval as the sample size increases?
A. The width increases
B. The width decreases.
C. The width does not alter with sample size.
D. Not enough information to determine.
Reply: Since the sample size increasing will decrease our standard error, our margin of error decreases too. A decreased margin of mistake means our confidence interval becomes more narrow.
7. Which test statistic practise we always use when performing a hypothesis test for ways?
A. z score
B. t score
C. chi square score
D. p-value
Respond: Any inferential procedure using means will use a t score every bit its critical value or test statistic.
8. When performing a hypothesis test at the α=0.05 level, what would authorize united states of america to reject the nothing hypothesis?
A. p-value<0.05
B. p-value >0.05
C. t score <0.05
D. t score>0.05
Answer: When comparing with the α level, in society to reject our cipher hypothesis, we need a p-value less than our α. A conclusion can be made using the t score, but we are typically looking for an farthermost test statistic (far abroad from 0) and 0.05 as a test statistic would non be unlikely.
9. Which of the following represents a possible aught hypothesis?
A. Ho: μ<55
B. Ho: ten-bar=55
C. Ho: μ=55
D. Ho: x-bar<55
Reply: Our null hypothesis is always a claim most the population hateful (μ) and our nix hypothesis is ever an equality statement.
10. What part(s) of a confidence interval question determines the critical value for a one sample t interval?
A. confidence level
B. sample size
C. sample mean
D. sample size and conviction level
Answer: Our disquisitional value takes two things into consideration: degrees of freedom and conviction level. Since we are using the family of t distributions here, our critical value changes every bit our sample size changes (which changes the degrees of freedom). Also, our confidence level irresolute adjusts our critical value considering it affects what the heart area is of our t distribution.
xi. A wildlife conservationist wants to estimate the length of crocodiles in the wild. To do and then, she takes a sample of 50 crocodiles and computes the following confidence interval of (14, 17) feet. What is the indicate guess?
A. 21
B. 15.5
C. 17
D. 14
Answer: To detect the point estimate when given a confidence interval, you are finding the midpoint of the interval. Add the two bounds and divide by 2 to take the average of the upper and lower bounds.
12. Find the t value for a 99% confidence interval of a sample size of 30.
A. 1.658
B. 2.756
C. 2.576
D. 1.96
Reply: To find the t score, y'all would accept the tail probability (0.005) and our df (39) and enter it into invT function in your calculator. Be conscientious not to make the fault of selecting the z score for a 99% confidence interval.
xiii. After performing a hypothesis exam at the α=0.1 level, I find that my culling hypothesis is statistically pregnant. At which other levels would our sample be statistically significant?
A. 0.15
B. 0.05
C. 0.03
D. 0.01
Answer: Since our p value is less than 0.1, information technology must also exist less than 0.15, merely we do not know for sure that information technology is less than 0.05, 0.01 or 0.03.
14. When we fail to reject the aught hypothesis and we should have rejected it, we have committed a __________.
A. Statistical Fallacy
B. Type i mistake
C. Type 3 mistake
D. Type 2 fault
Answer: When we fail TO reject and nosotros should accept, this is a type TWO mistake.
15. If I am performing a hypothesis examination at the α=0.05 level, what is the probability of committing a type 1 error?
A. 0.1
B. 0.95
C. 0.05
D. 0.5
Answer: The probability of committing a type 1 error is the aforementioned as the significance level. A type i mistake is made when we reject the null erroneously. Nosotros reject the nix when the p-value is less than 0.05. Basically, there is a 0.05 adventure of getting that p-value by random adventure, hence a 5% probability of rejecting the goose egg based on rare chance.
What can nosotros assist you lot do now?
- 🔍Bank check out all of the Unit of measurement eight Resources
- 🦘Jump to Unit eight Multiple Choice Questions
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🤝Connect with other students studying AP Stats with Hours
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