Exam 14: Logistic Regression

What is the null hypothesis being tested when analyzing data using multiple logistic regression with three explanatory variables?

Logistic regression is based on ________.

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. Is age a significant predictor of having had a recent mammogram? (Assume  = 0.05. )

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

Do women and men treat female and male children differently? An observational study was conducted near the primate exhibit at the Sacramento Zoo on weekends in 1988.The data are from 37 groups of three-one adult female,one adult male,and one toddler-in which the toddler was being carried.Recorded in the table below are the gender of the adult who was carrying the toddler and the gender of the toddler: Let x be the indicator variable We wish to fit a logistic regression model, ,where p is the binomial probability that the toddler being carried is a girl and log is the natural logarithm.The following (partial)SPSS output is available. Variables in the Equation Based on the data in the table,what is the estimate b₀ of ₀?

Do women and men treat female and male children differently? An observational study was conducted near the primate exhibit at the Sacramento Zoo on weekends in 1988.The data are from 37 groups of three-one adult female,one adult male,and one toddler-in which the toddler was being carried.Recorded in the table below are the gender of the adult who was carrying the toddler and the gender of the toddler: What proportion of the male adults was carrying a girl?

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 value of the test statistic and the P-value for the test of the hypotheses H₀: = 0 against H_a:  0?

Do women and men treat female and male children differently? An observational study was conducted near the primate exhibit at the Sacramento Zoo on weekends in 1988.The data are from 37 groups of three-one adult female,one adult male,and one toddler-in which the toddler was being carried.Recorded in the table below are the gender of the adult who was carrying the toddler and the gender of the toddler: Let x be the indicator variable We wish to fit a logistic regression model, ,where p is the binomial probability that the toddler being carried is a girl and log is the natural logarithm.The following (partial)SPSS output is available. Variables in the Equation What is a 90% confidence interval for the intercept ₀?

Do women and men treat female and male children differently? An observational study was conducted near the primate exhibit at the Sacramento Zoo on weekends in 1988.The data are from 37 groups of three-one adult female,one adult male,and one toddler-in which the toddler was being carried.Recorded in the table below are the gender of the adult who was carrying the toddler and the gender of the toddler: Let x be the indicator variable We wish to fit a logistic regression model, ,where p is the binomial probability that the toddler being carried is a girl and log is the natural logarithm.The following (partial)SPSS output is available. Variables in the Equation What is the value of the X² statistic for testing the hypotheses H₀: ₁ = 0 vs.H_a: ₁  0?

In a simple random sample,320 stay-at-home mothers are interviewed.The questions are all about their hobbies outside of raising their children.The number of mothers in the sample who enjoy scrapbooking in their spare time is 223.What are the odds that a stay-at-home mother enjoys scrapbooking?

How do men and women compare on a trip to the grocery store? A certain grocery list with a variety of items on it was given to 90 people with a family (who are used to shopping for more than one person).The total bill should be about $250.Each of the 90 people was sent to their grocery store of choice and their bill was categorized as either paying too much or not paying too much (e.g. ,a bill of $250 or less).The results,by gender,are shown below. Let x be the indicator variable We wish to fit a logistic regression model, ,where p is the binomial probability that the person paid too much for the groceries on the list. The following SPSS output is available. Variables in the Equation What is the equation of the estimated log odds?

A student survey reveals that only 564 of 1200 students surveyed voted in the past student government elections.What are the log odds that a student voted in the past student elections?

What are the degrees of freedom of the test used when analyzing data using multiple logistic regression with three explanatory variables?