Exam 14: Logistic Regression

Myopia (i.e. ,nearsightedness)is a result of environmental and genetic factors.In Singapore,the percent of military personnel having myopia increased dramatically over a 20-year period.Based on this fact,researchers wondered if the effect of the environment might be stronger and the genetic effect much less pronounced than previously thought.To study this issue,data from a random sample of 429 men,ages nineteen to twenty-five,in the Singapore military were obtained.Among other things,the men in the study were classified as to whether or not they had myopia and whether at least one of their parents had myopia.The results are presented in the table below. Of those men with myopia,what proportion had at least one parent with myopia?

What function can undo the natural log transformation?

Myopia (i.e. ,nearsightedness)is a result of environmental and genetic factors.In Singapore,the percent of military personnel having myopia increased dramatically over a 20-year period .Based on this fact,researchers wondered if the effect of the environment might be stronger and the genetic effect much less pronounced than previously thought.To study this issue,data from a random sample of 429 men,ages nineteen to twenty-five,in the Singapore military were obtained.Among other things,the men in the study were classified as to whether or not they had myopia and whether at least one of their parents had myopia.The results are presented in the table below. Let x be the indicator variable We wish to fit a logistic regression model, ,where p is the binomial probability that a man in the Singapore military has myopia and log is the natural logarithm. Based on the data in the table,what is the estimate b₀ of ₀?

In logistic regression with one explanatory variable,what is the P-value when the X² test statistic has a value of 5.35?

A student survey reveals that only 564 of 1200 students surveyed voted in the past student government elections.After closer inspection,it is discovered that 226 female students voted and 338 male students voted.Of the 1200 students participating in the survey,710 were female and 490 were male.What is the odds ratio of a male student voting in the past student elections to a female student voting in the past student elections?

What is the distribution of the test statistic when analyzing data using multiple logistic regression with three explanatory variables?

In a recent study,over 33,000 women were asked,"Did you have a mammogram within the last 2 years?" Despite the benefits of screening,about 30% of respondents indicated that they had not had a recent mammogram.The dependent/outcome variable was the proportion of women who reported a recent mammogram.In addition,the following information was collected on each individual: age (40-49,50-64,65-74,75-84),race/ethnicity (Latina,Non-Latina African American,Non-Latina Asian/Pacific Islander,Non-Latina White,and Non-Latina other race/ethnicity),marital status (married or living with partner vs.not currently married),history of breast cancer (yes vs.no),self-rated health (excellent,very good,good,fair,poor),currently with health insurance (yes vs.no),and having a usual source of care (yes vs.no).All variables were treated as categorical (e.g. ,coded as 1 or 0 for each category).A multiple logistic regression model was fitted to the data to predict the probability a woman had a recent mammogram.Software output from SAS is shown below. What is the sample proportion of women who did not have a mammogram within the last 2 years?

In logistic regression,there can be _____ explanatory variable(s).

Myopia (i.e. ,nearsightedness)is a result of environmental and genetic factors.In Singapore,the percent of military personnel having myopia increased dramatically over a 20-year period.Based on this fact,researchers wondered if the effect of the environment might be stronger and the genetic effect much less pronounced than previously thought.To study this issue,data from a random sample of 429 men,ages nineteen to twenty-five,in the Singapore military were obtained.Among other things,the men in the study were classified as to whether or not they had myopia and whether at least one of their parents had myopia.The results are presented in the table below. Let x be the indicator variable We wish to fit a logistic regression model, ,where p is the binomial probability that a man in the Singapore military has myopia and log is the natural logarithm. What is the odds ratio?

In a recent study,over 33,000 women were asked,"Did you have a mammogram within the last 2 years?" Despite the benefits of screening,about 30% of respondents indicated that they had not had a recent mammogram.The dependent/outcome variable was the proportion of women who reported a recent mammogram.In addition,the following information was collected on each individual: age (40-49,50-64,65-74,75-84),race/ethnicity (Latina,Non-Latina African American,Non-Latina Asian/Pacific Islander,Non-Latina White,and Non-Latina other race/ethnicity),marital status (married or living with partner vs.not currently married),history of breast cancer (yes vs.no),self-rated health (excellent,very good,good,fair,poor),currently with health insurance (yes vs.no),and having a usual source of care (yes vs.no).All variables were treated as categorical (e.g. ,coded as 1 or 0 for each category).A multiple logistic regression model was fitted to the data to predict the probability a woman had a recent mammogram.Software output from SAS is shown below. What category of general health is a significant predictor of having had a recent mammogram? (Assume  = 0.05. )

In a recent study,over 33,000 women were asked,"Did you have a mammogram within the last 2 years?" Despite the benefits of screening,about 30% of respondents indicated that they had not had a recent mammogram.The dependent/outcome variable was the proportion of women who reported a recent mammogram.In addition,the following information was collected on each individual: age (40-49,50-64,65-74,75-84),race/ethnicity (Latina,Non-Latina African American,Non-Latina Asian/Pacific Islander,Non-Latina White,and Non-Latina other race/ethnicity),marital status (married or living with partner vs.not currently married),history of breast cancer (yes vs.no),self-rated health (excellent,very good,good,fair,poor),currently with health insurance (yes vs.no),and having a usual source of care (yes vs.no).All variables were treated as categorical (e.g. ,coded as 1 or 0 for each category).A multiple logistic regression model was fitted to the data to predict the probability a woman had a recent mammogram.Software output from SAS is shown below. What are the odds that a woman did not have a mammogram within the last 2 years?

In logistic regression,the test statistic used to test the null hypothesis that ₁ = 0 is sometimes called a(n)_______.

What information is needed to compute odds?

A study was undertaken to assess the quality of cheese as determined by a panel of taste testers.The tasters rated samples of cheese as being acceptable or not acceptable.Those same samples of cheese were analyzed with respect to several variables,one of which was the untransformed concentration of lactic acid,designated as Lactic.A logistic regression was fitted relating the log odds that the cheese was acceptable to the explanatory variable Lactic.The following partial computer output is provided. A sample of cheese was analyzed and the variable Lactic was found to have the value 16.5.At this level of concentration of lactic acid,what are the odds that the cheese will be deemed to be acceptable?

In logistic regression,the log of the odds is applied to which variable?

In a small college town,many apartments and student houses are claimed to be in good condition by their owners and landlords.A formal inspection of 350 of these student apartments and houses reveals that 212 of them do not pass the regulation guidelines.What are the odds that a student apartment or house does pass the regulation guidelines?

In multiple logistic regression,the response variable takes on _____ possible value(s).

Which of the following statements about logistic regression is/are TRUE?

Suppose the proportion of students in a simple random sample who own a tablet computer is .80 and the proportion of students that do not own a tablet is .20.What are the odds that a student does not own a tablet?

A study was undertaken to assess the quality of cheese as determined by a panel of taste testers.The tasters rated samples of cheese as being acceptable or not acceptable.Those same samples of cheese were analyzed with respect to several variables,one of which was the untransformed concentration of lactic acid,designated as Lactic.A logistic regression was fitted relating the log odds that the cheese was acceptable to the explanatory variable Lactic.The following partial computer output is provided. What is the meaning of the entry 0.6332 in the above table under Estimate for the variable Lactic?