Graphs Experiments and Studies Sampling and Surveys Center and Spread Normal Distributions

Graphs – 100 The median percent of obese adults in these 45 states is: (a)17.69% (b)17.8% (c)17.85% (d)17.9% (e)23% [insert answer] Answer: B

Graphs Which point on this boxplot is the first quartile of the distribution? Answer: B

Graphs We see from the plot that the median number of calories in a beef hot dog is about (a)190 (b)179 (c)153 (d)139 (e)129 Answer: C

Graphs The mean is a)less than the median because the distribution is skewed left b)greater than the median because the distribution is skewed left c)less than the median because the distribution is skewed right d)equal to the median e)impossible to determine Answer: A

Graphs Answer: B Which of the following best describes the given stemplot? A.Skewed right, use the mean and standard deviation to describe the data B.Skewed right, use the 5 number summary to describe the data C.Skewed left, use the mean and standard deviation to describe the data D.Skewed left, use the 5 number summary to describe the data E.Symmetric, use either summary to describe the data

Experiments and Studies In a study subjects were randomly assigned to wear a new bug repellant or no repellant. The number of bug bites were recorded for each subject. This is an example of A.A Sample Survey B.An Observational Study C.An Experiment D.A Simple Random Sample E.A Stratified Sample Answer: C

Experiments and Studies Which of the following is not a principal of experimental design? A.Control B.Randomization C.Replication D.Blocking E.Using many subjects to reduce chance variation Answer: D

Experiments and Studies Researchers interested in the effects of a new drug to help people quit smoking wonder whether or not a person is depressed would affect the outcome. They enlist 300 subjects without depression and 140 subjects with depression. Within each group they randomly assign each person the new drug or a placebo. They then record whether the person was able to quit smoking successfully. Breaking the subjects into two groups first is an example of: A.Randomization B.Stratifying C.Blocking D.Replication E.Systematic Sampling Answer: C

Experiments and Studies Answer: C The difference between an experiment and an observational study is A.Observational studies don't have explanatory and response variables. B.Experiments don't have placebos. C.An experiment imposes treatments on subjects, while an observational study measures variables of interest without attempting to influence responses. D.Experiments are double-blind, while observational studies are only single-blind. E.All of the above.

Experiments and Studies Answer: E A magazine article on preventing cancer says, "Eating one serving of tofu a week may cut your risk of breast cancer 15 percent, recent research suggests." If the data comes from an observational study, then A.the results must be false. B.the results must be true. C.there may be lurking variables. D.perhaps those who choose to eat more tofu are, for some reason, less susceptible to breast cancer than those who didn't. E.Both (c) and (d) are true.

Sampling and Surveys – 100 Answer: C In a recent poll, adults were asked how many cell phones they had owned in their lifetime. The variable being measured is A.the number of adults polled B.the number of adults with cell phones C.the number of cell phones a person has owned D.The number of cell phones a person owns right now E.the age of the person surveyed

Sampling and Surveys Answer: D A quality control inspector wants to check the quality of the coffee beans being produced. He goes to each of 10 batches of beans that had been roasted that day and takes a random cupful of coffee beans to be used for testing. This is an example of which kind of sampling method? A.Simple Random Sampling B.Systematic Random Sampling C.Voluntary Response D.Stratified Random Sampling E.Blocking

Sampling and Surveys Answer: E An environmental watchdog group posted on their website a survey question asking readers to answer the following question, "Given the recent oil spill in the Gulf of Mexico and the subsequent environmental disaster, should we continue to allow oil companies to plunder and destroy the ocean depths for oil?" The results of this survey may not be accurate because of A.Nonsampling error B.Undercoverage C.Wording of the Question D.Voluntary Response Bias E.All the above

Sampling and Surveys Answer: C When we take a census, we collect data from A.a stratified random sample B.every individual selected in a simple random sample C.every individual in the population D.a voluntary response sample E.a convenience sample

Sampling and Surveys Answer: D A political polling group took a simple random sample of a 250 residents of a large city asking if they would be voting for the Republican or Democratic candidate in the upcoming election for mayor. They found that 130 would be voting for the Democrat. The group reported that 52% of the voters would be voting for the Democratic candidate for mayor. The actual result was that 58% voted for the Democratic candidate. Which of the following is correct? A.The 52% and 58% are both parameters B.The 52% and 58% are both statistics C.The 52% is a parameter; the 58% is a statistic D.The 52% is a statistic; the 58% is a parameter E.It is impossible to tell which is a parameter or statistic

Center and Spread Answer: D The 11 states in the Midwest have these percents of obese adults: The mean and standard deviation of these values are about: A and 1.60 B and C and D and 1.68 E and 11

Center and Spread Answer: D Fifty percent of the observations will be at or above the A.maximum B.standard deviation C.mean D.median E.first quartile

Center and Spread Answer: C Using the 1.5  IQR Rule, identify any outliers. A.189 B.189 and 625 C.625 D.There are no outliers E.We can’t use the 1.5  IQR rule because the data set is small.

Center and Spread Answer: B If a set of observations has a standard deviation that is zero, which of the following must be true? A.The mean is also zero. B.All the values are exactly the same. C.There is no relationship between the observations. D.The standard deviation can never be zero. E.The data is skewed.

Center and Spread Answer: C A set of observations has a mean of 145 and a standard deviation of 32. If each observation has 15 added to it's value what would happen to the mean and standard deviation? A.They would both stay the same. B.Both statistics would increase by 15. C.Only the mean would increase by 15; the standard deviation would stay the same. D.Only the standard deviation would increase by 15; the mean would stay the same. E.It is impossible to figure out without having the actual data. Daily Double!

Normal Distributions Answer: C What is the standard score for an observational value of 49 from a distribution with mean 32 and standard deviation of 12? A.  B.  C D

Normal Distributions Answer: A The weights of male Doberman Pinschers is normally distributed with a mean of 77 lbs. and a standard deviation of 4.3 lbs. What proportion of male Doberman Pinschers weigh less than 65 lbs.? A B C D

Normal Distributions Answer: A The weights of male Doberman Pinschers is normally distributed with a mean of 77 lbs. and a standard deviation of 4.3 lbs. What proportion of male Doberman Pinschers are between 68 and 79 lbs.? A B C D

Normal Distributions Answer: C The weights of male Doberman Pinschers is normally distributed with a mean of 77 lbs. and a standard deviation of 4.3 lbs. What would be the lowest weight of the top 10% of Doberman Pinschers? A.80 lbs B.85.6 lbs C.82.5 lbs D.90 lbs

Normal Distributions Answer: A The weights of male Doberman Pinschers is normally distributed with a mean of 77 lbs. and a standard deviation of 4.3 lbs. Find the IQR of weights. A.5.8 lbs. B.6.0 lbs. C.74.1 lbs D.79.9 lbs