Topic 8
Topic 9
Conceptual
Conceptual
Topic 9 Math
Topic 10 Conceptual
Topic 10 Math
100
The above data shows students' choices for their favorite movie drama. Given that a student likes documentaries, what's the probability that the student is a sophomore?
What is .27 (27/100)?
100
When you take all possible samples of a given size N from a population, calculate a statistic on all samples, and arrange the statistics into a distribution, you are creating a _______?
What is sampling distribution?
100
47.8% of students at OU are from Oklahoma. Suppose you take all possible samples of size N=300 OU students, calculate the proportion of students from Oklahoma on each sample, and then arrange these statistics into a sampling distribution. The mean of this sampling distribution is ____?
What is .478?
100
Two confidence intervals are calculated for two samples from a given population. Assume the confidence level is fixed at 99%. Compared to the smaller sample, the confidence interval for the larger sample will be:
What is narrower?
100
You randomly sample 100 people and find out they have a mean age of 30, with a standard deviation of 5. What is a 95% confidence interval for the population mean?
What is 29 to 31?
200
What's the probability of flipping a coin five times and getting a HTTHH?
What is .03125 (1/32)?
200
Assuming everything else is equal, as the sample size decreases, the standard error of the mean ______.
What is increases?
200
A small town has 5000 families. The average number of children per family is mu = 2.5, with a standard deviation of sigma = 3. A sampling distribution of the mean for N = 36 is developed for this population. What is the mean of the sampling distribution of the mean?
What is 2.5?
200
A 2018 sample of 130 college students randomly selected from a university indicated that 91 were sexually active.The researcher calculated a 95% confidence interval for the data to be .62 to .78. If the researcher had created a 90% confidence interval instead, the interval would have been:
What is narrower?
200
A random sample of 100 students from the University of Oklahoma had a sample mean ACT score of 24 with a sample standard deviation of 3.5 Construct a 95% confidence interval for the population mean ACT score of University of Oklahoma students.
What is 23.3 to 24.7?
300
The following table shows students' responses to their favorite movie genre. Juniors are ____ likely to choose dramas than seniors.
What is more?
300
If sampling distributions of sample means are examined for samples of size 2, 16, and 50, you will notice that as n increases in size, the shape of the sampling distribution appears more like that of the:
What is the normal distribution?
300
The department of transportation recorded all taxi cab rides in OKC over the course of a year. They found that the average taxi cab ride is 13 minutes long with a standard deviation of 3.2. Suppose you take a random sample of 100 of the taxi cab rides from that year. There would be a 99.7% chance that the length of the taxi cab ride in your sample would be between ______ and ______ minutes. Wait to round until the very end and then round to two decimal places.
What is 12.04 and 13.96?
300
A researcher conducts an experiment and reports a 95% confidence interval for the mean. Which of the following must be true?
1. 5% of the measurements should be considered outliers.
2. 95% of the time, the sample statistic will produce an interval that contains the population mean.
3. 95% of the measurements will be between the upper and lower limits of the confidence interval.
4. 95% of the measurements can be considered valid.
What is statement 2?
300
A teacher administers a standardized math test to his class of 75 students. The mean score (out of 300 possible points) is 235. From previous studies, you know that the population standard deviation is 28. Using the sample data given, calculate a 95% confidence interval for the mean.
What is 228.54 to 241.46?
400
Suppose the probability of the OKC winning the Thunder is .42 and that the probability of it raining today is .10. Knowing that these events are independent, what is the probability of them both happening?
What is .042?
400
Which of the following statements is false?
Statement One: The standard error of the sampling distribution of proportion is equal to the population proportion times one minus the population proportion, divided by the sample size, and then take the square root of the whole thing.
Statement Two: The standard error of the sampling distribution of the mean is equal to the population standard deviation divided by the square root of N.
Statement Three: The mean of the sampling distribution of proportion is equal to the population mean.
Statement Four: The mean of the sampling distribution of the mean will be the same for a population in which all samples of size 5 are taken and for the same population in which all samples of size 55 are taken.
What is statement three?
400
A small town has 3500 families. The population mean (mu) number of children per family is = 3, with a population standard deviation (sigma) = 0.60. A sampling distribution of the mean for n= 80 is developed for this population. What is the standard deviation of this sampling distribution? Round to two decimal places.
What is .07?
400
A researcher is trying to estimate the population mean weight (in ounces) of computer chips produced by a factory. She randomly samples 200 computer chips and calculates a sample mean weight of 7.8 ounces. She then computes a 95% confidence interval for the mean weight (in ounces) of computer chips produced by the factory. The interval is 6.7 to 8.9. Which of these is a correct interpretation of this interval?
1. We can be 95% confident that all computer chips weigh between 6.7 and 8.9 ounces.
2. We are 95% confidence that the interval 6.7 to 8.9 covers our sample mean weight.
3. The true population mean weight lies between the interval 6.7 to 8.9.
4. There's a 95% chance that our sample mean is the correct estimate of the population mean.
5. We are 95% confident that the interval 6.7 to 8.9 covers the population mean weight.
What is statement five?
400
Researchers were interested in the population proportion of undergraduate students at the University of Oklahoma who are from the state of Oklahoma. They took a random sample of 200 students and found that 150 of them are from Oklahoma. They calculated a 95% confidence interval for the population proportion p to be .66 to .84. What would you estimate the standard error of the proportion to be? Don't round.
What is .045?
500
In a city of 381,000 people, a disease affects 12% of the population. A test for the disease has a sensitivity of 90% and a specificity of 77%. Given that a person tests positive for the disease, what is the probability that they actually have the disease?
What is .348 (34.8%)?
500
Imagine that we have a population that is negatively (left) skewed that has a mean of 35 and a standard deviation of 1.75. Using a computer simulation program, Sarah creates a sampling distribution of size n=40 from this population and Paula creates a sampling distribution of size n=20 from this population. How would Sarah's and Paula’s sampling distributions compare to each other in terms of their means, standard error, and shape? (Tell me whether the means would be the same, or whether one of them would be bigger or smaller, and specify which; whether the standard errors would be the same or whether one of them would be bigger or smaller and specify which, and tell me whether the shapes of their distributions would be the same or different and specify the shape.)
What is they would have the same mean, Sarah's sampling distribution would have a smaller standard error, and Sarah's distribution would be normal in shape, while Paula's would be negatively skewed.
500
A recent poll of all 133,000 Norman residents found that 28,000 regularly attend the Norman Art Walk on the Second Friday of every month. If I create a sampling distribution by drawing all possible samples of size N = 100 from the population of Norman, the mean of my sampling distribution will be ____ and the standard deviation will be _____. Round to two decimal places.
What are .21 and .04?
500
Which of the following statements is not true regarding a 95% confidence interval for the mean of a population?
1. In 95% of all samples, the sample mean will fall within 2 standard errors of the true population mean.
2. 95% of the population means will lie within 2 standard errors of the sample mean.
3. In 95% of all samples, the true population mean will be within 2 standard errors of the sample mean.
4. If you add and subtract two standard errors to and from the sample mean, in 95% of all cases, you will have captured the true population mean.
What is statement two?
500
You randomly select 575 citizens of the US and find that 50 of them watch The Wheel of Fortune each night. What is the 95% confidence interval for the population proportion of those who watch Wheel of Fortune each night? Round to two decimal points at the end.
What is .06 to .11?