The time taken for healthy Canadian adults to complete a logic problem is believed to be Normally distributed with mean 40 seconds and standard deviation 4 seconds. It is of interest to investigate whether UBC students perform better on average than healthy adult Canadians, so the logic problem is given to a sample of 80 UBC students, and their times to solution are recorded. Part a) Which of the following is/are parameter(s) of interest with respect to the new investigation here? (Select all that apply) OA. 40 seconds B. 4 seconds C. The variance of the times for all UBC students to complete the logic problem. O D. The mean time for all UBC students to complete the logic problem. OE. The mean time for the 80 UBC students to complete the logic problem. OF. 80 G. None of the above Part b) In testing a hypothesis about a parameter of interest, what would your null hypothesis be? O The mean time taken to solve the logic problem by healthy Canadian adults is 40 seconds. O The mean time taken to solve the logic problem by healthy Canadian adults is greater than 40 seconds. O The mean time taken to solve the logic problem by healthy Canadian adults is less than 40 seconds. O The mean time taken to solve the logic problem by healthy Canadian adults is different from 40 seconds. O The mean time taken to solve the logic problem by UBC students is greater than 40 seconds. O The mean time taken to solve the logic problem by UBC students is less than 40 seconds. O The mean time taken to solve the logic problem by UBC students is different from 40 seconds. • The mean time taken to solve the logic problem by UBC students is 40 seconds. Part c) You would take the alternative hypothesis to be: one-sided, left-tailed O two-sided. O one-sided, right-tailed. Oit does not matter whether we take a one-sided or two-sided altemative.

The first blank for both questions is: "estimate of the standard ('distance' or 'score' or 'mean')" Second blanks: "...between a ('sample mean' or 'sample mean difference' or 'score')"  Third Blanks: "...and the ('population mean difference' or 'population mean' or sample mean')" The choices are the same for the corresponding blanks, first, second and third.

If you look at the differences between the means, once with 10 participants and one mean with 20 participants. (same data set) One mean difference is very large, but non-significant and the other is very small, but came out significant. What could be the reason for this outcome? (My difference in means was with 10 participants: -1.1 and with 20 participants: -5.1)

Question 4The researcher wishes to use graphical descriptive methods to present summaries of the data on each of the two variables: hours worked per week and yearly income, as stored in file HOURSWORKED.jpga) The number of observations (n) is 65 individuals. The researcher suggests using 7 class intervals to construct a histogram for each variable. Explain how the researcher would have decided on the number of class intervals (K) as 7. b) The researcher suggests using class intervals as 10 < X ≤ 15, 15 < X ≤ 20, …, 40 < X ≤ 45 for the hours per week variable and class intervals 40 < X ≤ 45, 45 < X ≤ 50, ..., 70 < X ≤ 75 for the yearly income variable. Explain how the researcher would have decided the width of the above class intervals (or class width). c) Draw and display a histogram for each of the two variables using appropriate BIN values from part (b) and comment on the shape of the two distributions.

For the given scenario, determine the type of error that was made if any.(begin by determining the null and alternative hypothesis). A new whitening toothpaste advertises for shades as the mean number of shades the toothpaste whitens your teeth. One user claims that the mean number of shades the toothpaste whitens your teeth is different from four shades. The user conducts a hypothesis test and fails to reject the null hypothesis. Assume that in reality, the mean number of shades the two piece white is your teeth is for shade. Was an error made? If so, what type? A, B, C? A.Yes; type 2 error B.Yes; type 1 error C.No; correct decision

Let's talk that scenario and work with some fictional data from it: Let's imagine there was a question on the survey that asks "On average, how many times a day do you worry about COVID-19, either for yourself, family, or community? Below is some data for 10 respondents. In the space below,describe all of the steps you would use to calculate the appropriate type of t-test (independent or paired samples), given we want to compare Trump voters to Clinton voters. For this question, just list the steps - do not do any calculations. That will be in the next question. Your list will have at least 6 steps. Just get as far as the t-statistic; no need to describe hypothesis testing steps in this problem.