1. If one wants to test whether there is a difference in mean scores before and...
If one wants to test whether there is a difference in mean scores before and after an exam, which will be an appropriate test to use? a) one sample z test b) one sample t test c) paired t test d) two sample independent t test If X is a random variable following a Uniform(a,b) distribution, which option represents an approxi- mate shape of its density function? a) straight vertical line between a and b b) straight horizontal line between...
Multiple Choice Questions Choose the one alternative that best completes the statement or answers the question (2.5 points each). You do not need to justify your answers. A If one wants to test whether there is a difference in mean scores before and after an exam, which will be an appropriate test to use? a) one sample z test b) one sample t test c) paired t test d) two sample independent t test B If X is a random...
21) A researcher wants to know whether there is a difference in the physical activity level of children during the morning and afternoon. He observes a total of 40 children (20 boys and 20 girls) from randomly selected schools during morning and afternoon recess and gives each child a score (out of 50) based on how much of the time they spend sitting, standing, walking or running. Each child receives a score in the morning and another in the afternoon....
A medical researcher wants to determine whether a drug changes the body’s temperature. Seven test subjects are randomly selected, and the body temperature (in degrees Fahrenheit) of each is measured. The subjects are then given the drug and after 20 minutes, the body temperature of each is measured again. The results are listed below. Use significance level α = 0.05, and we assume that the body temperatures are normally distributed. Show your work space provided below: t-Test: Paired Two Sample...
The owner of an Italian restaurant has redesigned the menu and wants to see if the amount customers spend (on average) will be greater with the new menu. He records the sales the week before the change and the sales the week after the change. Using the sample means and standard deviations for the two weeks, which statistical inference should he perform? A. a t test for paired samples (using differences) B. the owner should compute the mean dining bill...
1- Choose the functions that should be used to test whether your dataset meets the assumptions for a two-sample t-test. Select one or more: a. mean() b. normalTest() c. qt() d. var.test() e. var() 2- Which of the following is the name of a mandatory argument to the function read.csv in R? Select one: a. file b. sep c. header d. quote 3- Match the type of comparison to its appropriate null hypothesis. The sample mean is not different from...
-If Argyle says that she has collected data that only tell her whether the cases are the same or different, one can accurately say that she has collected data on the _____ level. nominal ratio ordinal interval -which of these is an advantage of using a transformed score when reporting the score of an individual case? Transformed scores will be reported on the nominal level. Transformed scores will allow the mean score to be reported. Transformed scores provide a measure...
In order to determine whether or not a driver's education course improves the scores on a driving exam, a sample of 6 drivers were given the exam before and after taking the course. The results are shown below. Assume the population of differences is normally distributed. Let d = Score After - Score Before. Driver Score Before the Course Score After the Course 1 83 87 2 89 88 3 93 91 4 77 77 5 86 93 6 79...
You have a sample of 45 3rd graders who took a reading comprehension test before and after participating in a reading program. The scores on the reading comprehension test are then compared. What is the appropriate test to use? one-sample z-test two-sample t-test for dependent samples none of the above two-sample t-test for independent samples
One-Sample Test Test Value = 1 t df Sig. (2-tailed) Mean Difference 95% Confidence Interval of the Difference Lower Upper What is your gender? -11.787 79 .000 -.637 -.75 -.53 Hypothetical exam scores (out of 100) 98.022 79 .000 84.438 82.72 86.15 Which of the following is the null hypothesis? Highlight or circle your answer. [.5 points] a) H0: µ1 = µ2 b) H1:...