Exam 10: Associations Between Categorical Variables

Use the following table to answer the question. The following table summarizes the outcomes of a study that researchers carried out to determine if females expressed a greater fear of public speaking then males. -Calculate the percentage of people in the study that did not express a fear of public speaking. Round to the nearest tenth of a percent.

Use the following information to answer the question. Almas caviar is a very expensive Iranian brand of Beluga sturgeon caviar. A one pound gold- plated tin typically costs $12,000 or more. In a blind taste test, a group of food experts tasted four premium Beluga sturgeon caviars, with the most expensive one being Almas caviar. When asked to pick the most expensive caviar, 141 got it right and 79 got it wrong. -Calculate the observed value of the chi- square statistic by hand. Show all your work. Round to the nearest hundredth.

Suppose a random sample of 1,105 adults were asked about their opinion regarding salaries of full- time employees at a local state funded university. Respondents were asked whether salaries at the university were (a)too low, (b)adequate, or (c)too high. Respondents were also classified by income level. If we wanted to test whether there was an association between the response to the question and income level, would this be a test of homogeneity or of independence?

Use the following table to answer the question. The following table summarizes the outcomes of a study that researchers carried out to determine if females expressed a greater fear of heights than males. -How many categorical variables are summarized in the table?

Use the following information to answer the question. The data in the top row of the table shows the number of days for which the respondent participated in an outdoor activity for at least thirty minutes in the previous 60 days. The respondents also reported their level of happiness; Very H means very happy, and so on. -Suppose you want to test the hypothesis that happiness level is associated with level of daily outdoor activity. Can a chi- square test for independence be used to test the hypothesis? Explain why or why not.

Use the following information to answer the question. A dowsing rod is a "Y" or "L" shaped instrument that some believe can find ground water. Many dowsers today use a pair of simple L- shaped metal rods. One rod is held in each hand, with the short arm of the L held upright, and the long arm pointing forward. When something is found, the rods cross over one another making an "X" over the found object. Skeptics of dowsing conducted an experiment to see if dowsing rods could find ground water. Five identical 3 foot by 3 foot plots of land were sectioned off and a container of water was buried in one of the plots. Below is a summary of the experiment results and the output for the goodness- of- fit test. -Choose the correct null and alternative hypothesis.

Choose the statement that is not true about the chi- square distribution or choose (d)if all the statements are true.

Choose the statement that is not true about the chi- square distribution or choose (d)if all the statements are true.

Use the following table to answer the question. The following table summarizes the outcomes of a study that researchers carried out to determine if females expressed a greater fear of heights than males. -What fraction represents the proportion of people in the study who expressed a fear of heights?

Use the following table to answer the question. The following table summarizes the outcomes of a study that researchers carried out to determine if females expressed a greater fear of public speaking then males. -Describe the categorical variables that are summarized in the table. Describe one association that could be tested based on the information from the table.

Use the following information to answer the question. Lambda olive oil is touted as the "World's most expensive olive oil." A twelve ounce bottle typically costs fifty dollars or more. In a blind taste test, a group of food experts tasted three premium olive oils, one of which was Lambda olive oil. When asked to pick the Lambda olive oil, 84 got it right and 87 got it wrong. -If this group were just guessing, how many people (out of 171)would be expected to guess correctly?

Use the following table to answer the question. The following table summarizes the outcomes of a study that researchers carried out to determine if females expressed a greater fear of flying than males. -What fraction represents the proportion of people in the study who did not express a fear of flying?

Use the following information to answer the question. The data in the top row of the table shows the number of vacation days taken by the respondent in the previous 90 days. The respondents also reported their level of happiness; Very H means very happy, and so on. -The following table shows the data after merging categories so that there are two column categories (0- 1 vacation days and 2 or more vacation days), and two row categories (happy and unhappy). Expected values for each cell are also shown in parentheses. Test the hypothesis that there is an association between happiness and number of vacation days taken in the last 90 days, using a significance level of 0.05. State the value of the test statistic rounded to two decimal places and state whether the p- value is closer to zero or one.

Use the following information to answer the question. Bellei Extravecchio Balsamico Tradizionale is a very expensive brand of balsamic vinegar. A twelve ounce bottle typically costs two- hundred dollars or more. In a blind taste test, a group of food experts tasted three premium balsamic vinegars, with the most expensive one being Bellei Extravecchio Balsamico Tradizionale. When asked to pick the most expensive balsamic vinegar, 92 got it right and 76 got it wrong. -Calculate the observed value of the chi- square statistic. Round to the nearest hundredth.

Use the following information to answer the question. Lambda olive oil is touted as the "World's most expensive olive oil." A twelve ounce bottle typically costs fifty dollars or more. In a blind taste test, a group of food experts tasted three premium olive oils, one of which was Lambda olive oil. When asked to pick the Lambda olive oil, 84 got it right and 87 got it wrong. -Calculate the observed value of the chi- square statistic. Round to the nearest hundredth.

Choose the statement that is not true about the chi- square test or choose (d)if all the statements are true.

Choose the statement that is not true about Fisher's Exact Test or choose (d)if all the statements are true.

Suppose a random sample of 1,105 adults were asked about their opinion regarding salaries of full- time employees at a local state funded university. Respondents were asked whether salaries at the university were (a)too low, (b)adequate, or (c)too high. Respondents were also classified by income level. State the correct hypothesis to test whether there is an association between the response to the questions and income level.

Choose the statement that is not true about the chi- square test or choose (d)if all the statements are true.

Use the following information to answer the question. A dowsing rod is a "Y" or "L" shaped instrument that some believe can find ground water. Many dowsers today use a pair of simple L- shaped metal rods. One rod is held in each hand, with the short arm of the L held upright, and the long arm pointing forward. When something is found, the rods cross over one another making an "X" over the found object. Skeptics of dowsing conducted an experiment to see if dowsing rods could find ground water. Five identical 3 foot by 3 foot plots of land were sectioned off and a container of water was buried in one of the plots. Below is a summary of the experiment results and the output for the goodness- of- fit test. -Test the hypothesis that the dowsing rods worked better at locating ground water than guessing. Using a goodness- of- fit test and a 0.05 level of significance, choose the correct decision regarding the null hypothesis and conclusion statement.