27. A chi-square test of the relationship between personal perception of emotional health and

marital status led to rejection of the null hypothesis, indicating that there is a relationship

between these two variables. One conclusion that can be drawn is:

a. Marriage leads to better emotional health.

b. Better emotional health leads to marriage.

c. The more emotionally healthy someone is, the more likely they are to be married.

d. There are likely to be confounding variables related to both emotional health and

marital status.

28. A chi-square test involves a set of counts called "expected counts." What are the expected

counts?

a. Hypothetical counts that would occur of the alternative hypothesis were true.

b. Hypothetical counts that would occur if the null hypothesis were true.

c. The actual counts that did occur in the observed data.

d. The long-run counts that would be expected if the observed counts are representative.

29. Pick the choice that best completes the following sentence. If a relationship between two

variables is called statistically significant, it means the investigators think the variables are

a. related in the population represented by the sample.

b. not related in the population represented by the sample.

c. related in the sample due to chance alone.

d. very important.

30. Simpson's Paradox occurs when

a. No baseline risk is given, so it is not know whether or not a high relative risk has

practical importance.

b. A confounding variable rather than the explanatory variable is responsible for a change in

the response variable.

c. The direction of the relationship between two variables changes when the categories of

a confounding variable are taken into account.

d. The results of a test are statistically significant but are really due to chance.

14. | Demographics: Birth Rate and Death Rate In the following data pairs, A represents birth rate and B represents death rate per 1000-resident population. The data are paired by counties in the Midwest. A random sample of 16 coun- ties gave the following information (Reference: County and City Data Book, U.S. Department of Commerce): A: 12.7 13.4 12.8 12.1 11.6 11.1 14.2 15.1 B: 9.8 14.5 10.7 14.2 13.0 12.9 10.9 10.0 A: 12.5 12.3 13.1 15.8 10.3 12.7 11.1 15.7 B: 14.1 13.6 9.1 10.2 17.9 11.8 7.0 9.2 Do the data indicate a difference (either way) between population average birth rate and death rate in this region? Use a = 0.01.Lab2. In a population, the birth rate and death rate are calculated as follows: " Birth Rate = Number of Births + Population ' Death Rate = Number of Deaths + Population For example, in a population of 100,000 that has 8,000 births and 6,000 deaths per year, ' Birth Rate = 8,000 + 100,000 = 0.08 - Death Rate = 6,000 + 100,000 = 0.06 Design a Population class that stores a current population, annual number of births, and annual number of deaths for some geographic area. The class should allow these three values to be set in either of two ways: by passing arguments to a three-parameter constructor when a new Population object is created or by calling the setPopulation, setBirths. and setDeaths class member functions. In either case, if a population gure less than 2 is passed to the class, use a default value of 2. If a birth or death gure less than 0 is passed in, use a default value of 0. The class should also have getEirthRate and getDeathRate functions that compute and return the birth and death rates. 1lllfrite a short program that uses the Population class and illustrates its capabilities. Question 1. You are studying an endangered population of orchids, for which the birth rate b = 0.20 births per individual per year and the death rate d = 0.18 deaths per individual per year. The current population size (No) is 50 plants. A. A new shopping mall is planned that will eliminate part of the orchid habitat and reduce the current population to 25 individuals. Given that the probability of extinction for a population is: Pextinction = (d/b)No (where b and d = birth and death rates and No = initial population size), estimate the potential effect of the proposed development on the probability of extinction for this population. State your answer in words. Show your work. B. The logistic growth model accounts for the idea that in the real world, resource availability ultimately limits population growth. Is resource availability a density-dependent or density- independent factor in such a model? Explain.Q6) The owner of an online sports store wants to compare the sales with the geographical distribu- tion of the population. According to Statistics Canada (2006 Census), 7.2% of the population lives in the Maritimes, 23.9% in Quebec, 38.6% in Ontario, 17.2% in the Prairies and 13.1% in British Columbia. Here is the breakdown in a random sample of orders. Maritimes Quebec Ontario Prairies British Columbia 22 105 185 66 36 At the 1% level of significance, is the distribution of destination of the orders shipped reflective of that of the population