A research project was conducted to study the effect of a chemical on undesired insects.The researcher uses 6 dose levels,and at each level exposes 250 insects to the chemical and proceeds to count the number of insects that die.The researcher uses a binary logistic regression model to estimate the probability of death as a function of dose. Shown below is Minitab output from a logistic regression.
Coefficients
Term Coef SE Coef 95% CI Z-Value P-Value VIF
Constant -2.644 0.156 (-2.950,-2.338) -16.94 0.000
Dose 0.6740 0.0391 (0.5973,0.7506) 17.23 0.000 1.00
Odd Ratios for Continuous Predictors
Odds Ratio 95% CI
Dose 1.9621 (1.8173,2.1184)
The predicted probability that an insect will die when exposed to the second dose is ____.
A) 0.1246
B) 0.1446
C) 0.1857
D) 0.2737
E) 0.2945

Question

Quizplus · Accepted Answer

The logistic regression model is given by the formula: log(p/(1-p)) = β0 + β1*Dose. Using the coefficients provided, for the second dose (Dose = 2), the log-odds is calculated as -2.644 + 0.6740*2. Converting log-odds to probability gives the predicted probability of death.

A Research Project Was Conducted to Study the Effect of a Chemical