Identify whether the comparison is based on two independent samples or paired data:
A class survey is used to compare the GPAs of male and female students.
There are five children in your family (you and 4 siblings). Each night, two children are responsible to wash the dishes. To be fair, the children are selected by randomly pulling names from a hat. What is the probability that you will not have to wash the dishes?
Suppose you are taking a statistics course and a psychology course next semester. You like mathematics, so you believe that probability of getting an “A” in statistics is 0.8. On the other hand, psychology is not as interesting to you so the probability of getting an “A” in that class is 0.6. It will be challenging to manage both courses at the same time, so the probability of getting an “A” in both classes is 0.5. Are the events “A” in statistics and “A” in psychology independent?
A) No because 0.8*0.6 does not equal 0.5.
B) Yes because the grade in statistics does not affect the grade earned in psychology.
C) Yes because 0.8*0.6 does not equal 0.5.
A researcher randomly selected 20 classes of Grade-1 students from all elemetary schools in New York State to form a sample of students to study relationship bewteen nutrition and school performance. This sampling method is BEST defined as:
A) Simple random sampling
B) Cluster sampling
C) Stratified random sampling
D) Convenience sampling
Which of the following best describes the standardized (z) score for an observation?
A) It is the number of standard deviations the observation falls from the mean.
B) It is the most common score for that type of observation.
C) It is one standard deviation more than the observation.
D) It is the center of the list of scores from which the observation was taken.
A student does not study for a 10 question multiple choice quiz, with five answer choices for each question, so he randomly guesses an answer for every question. Which choice below describes how to find the probability that this student gets exactly 7 questions correct?
A) Find cumulative probability for 7 successes for a binomial variable with n = 10 and p = 7/10.
B) Find cumulative probability for 7 successes for a binomial variable with n = 10 and p = 1/5.
C) Find probability of 7 successes for a binomial variable with n = 10 and p = 1/5
D) Find probability of 7 successes for a binomial variable with n = 10 and p = 7/10
Correctly identify whether the following situations satisfy the conditions required to conduct a Binomial experiment. Rolling a die many times and observing whether the number obtained is even or odd
B) NOT Binomial
According to a recent survey approximately 25% of all college students work full time (that is, there is 0.25 probability for any given student to work full time). If the random variable X represents the number of students who work full time in samples of size 10, what is the expected value of X?
D) More information is needed
Which of the following is the main advantage of randomized experiments, when compared to observational studies?
A) The participants are more likely to stick with the experiment for the full duration
B) Cause and effect conclusions are possible.
C) Random assignment ensures that the two sample sizes are equal and that requirement is necessary.
D) Random assignment guarantees a more representative sample.
Which of the following statements is correct about a parameter and a statistic associated with repeated random samples of the same size from the same population?
A) Values of a parameter will vary from sample to sample but values of a statistic will not.
B) Values of both a parameter and a statistic may vary from sample to sample.
C) Values of a parameter will vary according to the sampling distribution for that parameter.
D) Values of a statistic will vary according to the sampling distribution for that statistic.