## A researcher has measured the combined anxiety scores and the marital

Question 1. 1. A researcher has measured the combined anxiety scores and the maritalsatisfaction levels of 20 married couples. Use her data and calculate the Pearson r correlationcoefficient.N ∑X ∑Y ∑XY ∑XÂ²∑YÂ²15 1045 763 52673 73593 39755(Points : 8)Question 2. 2. Interpret the correlation that you calculated in question 1. (Points : 5)Question 3. 3. Calculate and interpret r2 (the correlation of determination) for the correlation inquestion 1. (Points : 5)Question 4. 4. A researcher finds a correlation of .70 between heat and aggression. Sheconcludes that heat causes aggressive behavior. Is her conclusion valid? Why or why not?(Points : 4)Question 7. 7. Read the brief description of research given below and identify what might be thethreat to internal validity for that research study. Explain why youâve given your answer.A researcher is doing research on âhealthy eating habits.â College students are recruited toparticipate in the study. They are weighed at the beginning of the week and are randomlyassigned to a group which is asked to âtry to eat healthy meals this weekâ or to âkeep a detailedjournal of what you eat l and also record the calories for what you eat.â The beginning of thesecond week of the study, twice as many of the âjournal/calorieâ group do not return. (Points : 4)Question 8. 8. Kevin scored a 90 on his stats exam. The mean for the exam is 85 and thestandard deviation is 5. What is the z-score for his exam score? (Points : 4)Question 15. 15. A sample of 10 students was asked how many children they would like to haveone day. Their responses are below:0, 1, 2, 2, 3, 2, 0, 1, 3, 8a. What is the mean?b. What is the mode?c. What is the median?d. Are there any outliers?(Points : 8)Question 18. 18. For the following scenario, identify the independent and dependent variables.A researcher is interested in the effects of alcohol on reading comprehension. Participants aretold that they will be in a study examining reading comprehension. The participants signed aninformed consent stating that the study involves minimal risk. Participants are not told anythingelse about the study. Participants are given either a cup of water, a cup of rum and Coke, or 2cups of rum and Coke before beginning the experiment. Following consumption of the drink,participants read several paragraphs and answer questions about information in theparagraphs. The researcher records the participantsâ scores on the reading comprehensionexam. Participants are thanked by the researchers and sent on their way. All informationobtained is kept confidential. (Points : 4)Question 19. 19. For the following scenario, identify the independent and dependent variables.A study is conducted to determine whether physically fit persons sleep more hours than thosewho are not physically fit. Two groups of people were selected. One group consisted of peoplewho worked out 3 times a week. The other group consisted of people who did not work out atall. For one week, subjects slept in a sleep lab and an experimenter recorded number of hoursslept. (Points : 4)Question 20. 20. Describe/define variance and the standard deviation. How are the two related(e.g., if variance = 27 what is the standard deviation)? (Points : 4)Question 21. 21. A stats class has a mean IQ of 115. We know that μ = 100, σ = 16. The classsize (n) = 10. Calculate the z-score. (Points : 6)