A study examined the effect of body weight and origin (aviary or wild) on the length of the R1 central tail feather in male finches. The following model is proposed for predicting the length of the R1 feather from the bird's weight (in grams) and origin (aviary = 0, wild = 1): R1Lengthi = β0 + β1 (BodyWeighti) + β2 (Aviary0Wild1i) + εi Where the deviations εi were assumed to be independent and Normally distributed with mean 0 and standard deviation σ. This model was fit to a sample of 25 male finches. Using software, we obtained the following output: $\begin{array}{lrr} \text { Predictor } & \text { Coef } & \text { SE Coef } \\ \text { Constant } & 35.79 & 16.95 \\ \text { BodyWeight } & 2.826 & 1.030 \\ \text { Aviary0Wild1 } & -10.453 & 4.996 \end{array}$ $\begin{array}{l} \text { Predicted Values for New Observations }\\ \begin{array}{rrrcc} \text { NewObs } & \text { Fit } & \text { SE Fit } & 95 \% \mathrm{CI} & 95 \% \text { PI } \\ 1 & 76.22 & 4.32 & (67.26,85.17) & (54.35,98.09) \\ 2 & 86.67 & 2.75 & (80.96,92.38) & (65.91,107.43) \end{array} \end{array}$ $\begin{array}{l} \text { Values of Predictors for New Observations }\\ \begin{array}{crr} \text { NewObs } & \text { BodyWeight } & \text { Aviary0Wild } \\ 1 & 18.0 & 1.0 \\ 2 & 18.0 & 0.0 \end{array} \end{array}$ What is the best description of the interval (67.26, 85.17)?

A) A confidence interval for the mean tail-feather length of all male finches that weigh 18 g and are raised in an aviary B) A confidence interval for the mean tail-feather length of all male finches that weigh 18 g and are caught in the wild C) A prediction interval for the tail-feather length of one male finch that weighs 18 g and was raised in an aviary D) A prediction interval for the tail-feather length of one male finch that weighs 18 g and was caught in the wild A) A confidence interval for the mean tail-feather length of all male finches that weigh 18 g and are raised in an aviary B) A confidence interval for the mean tail-feather length of all male finches that weigh 18 g and are caught in the wild C) A prediction interval for the tail-feather length of one male finch that weighs 18 g and was raised in an aviary D) A prediction interval for the tail-feather length of one male finch that weighs 18 g and was caught in the wild

Researchers investigated the effects of acute stress on emotional picture processing and recall by randomly assigning 40 adult males to receive either a stressful cold stimulus or a neutral warm stimulus before viewing pictures. The researchers computed the relative brainwave amplitude (in microvolts, μV) for each subject viewing unpleasant versus neutral pictures. They also recorded how many pictures the subjects were able to recall 24 hours later. The following model is proposed for predicting the brainwave relative amplitude ("amplitude") from the number of images recalled ("recall"), the indicator variable reflecting the nature of the stimulus ("stress"), and an interaction term ("recall*stress"): Amplitudei = β0 + β1 (recalli) + β2 (stressi) + β3 (recall*stressi) + εi Where the deviations εi are assumed to be independent and Normally distributed with mean 0 and standard deviation σ. This model was fit to the sample of 40 adult males. Using software, we obtained the following output: $\begin{array} { l r r } \text { Predictor } & \text { Coef } & \text { SE Coef } \\ \text { Constant } & 4.795 & 1.329 \\ \text { recall } & - 0.1139 & 0.1069 \\ \text { stress } & - 4.262 & 2.205 \\ \text { recall* } \text { stress } & 0.4337 & 0.1677 \end{array}$ Predicted Values for New Observations New Obs Fit SEFit 95%CI 95% PI 1 3.731 0.624 (2.465,4.996) 2 3.656 0.508 (2.625,4.686) Values of Predictors for New Observations New New Obs recall stress recall*stress 1 10.0 1.00 10.00 2 10.0 0.00 0.00 Which of the following statements best describes the interval (-0.804, 8.115)?

A) A confidence interval for the mean brainwave relative amplitude of all adult men in a similar experiment exposed to a neutral stimulus and who remember 10 pictures B) A confidence interval for the mean brainwave relative amplitude of all adult men in a similar experiment exposed to a stressful stimulus and who remember 10 pictures C) A prediction interval for the brainwave relative amplitude of one adult man in a similar experiment exposed to a neutral stimulus and who remembers 10 pictures D) A prediction interval for the brainwave relative amplitude of one adult man in a similar experiment exposed to a stressful stimulus and who remembers 10 pictures A) A confidence interval for the mean brainwave relative amplitude of all adult men in a similar experiment exposed to a neutral stimulus and who remember 10 pictures B) A confidence interval for the mean brainwave relative amplitude of all adult men in a similar experiment exposed to a stressful stimulus and who remember 10 pictures C) A prediction interval for the brainwave relative amplitude of one adult man in a similar experiment exposed to a neutral stimulus and who remembers 10 pictures D) A prediction interval for the brainwave relative amplitude of one adult man in a similar experiment exposed to a stressful stimulus and who remembers 10 pictures

Researchers investigated the effects of acute stress on emotional picture processing and recall by randomly assigning 40 adult males to receive either a stressful cold stimulus or a neutral warm stimulus before viewing pictures. The researchers computed the relative brainwave amplitude (in microvolts, μV) for each subject viewing unpleasant versus neutral pictures. They also recorded how many pictures the subjects were able to recall 24 hours later. The following model is proposed for predicting the brainwave relative amplitude ("amplitude") from the number of images recalled ("recall"), the indicator variable reflecting the nature of the stimulus ("stress"), and an interaction term ("recall*stress"): Amplitudei = β0 + β1 (recalli) + β2 (stressi) + β3 (recall*stressi) + εi Where the deviations εi are assumed to be independent and Normally distributed with mean 0 and standard deviation σ. This model was fit to the sample of 40 adult males. Using software, we obtained the following output: $\begin{array}{lrr} \text { Predictor } & \text { Coef } & \text { SE Coef } \\ \text { Constant } & 4.795 & 1.329 \\ \text { recall } & -0.1139 & 0.1069 \\ \text { stress } & -4.262 & 2.205 \\ \text { recall* stress } & 0.4337 & 0.1677 \end{array}$ Predicted Values for New Observations New Obs Fit SEFit 95%CI 95% PI 1 3.731 0.624 (2.465,4.996) 2 3.656 0.508 (2.625,4.686) Values of Predictors for New Observations New New Obs recall stress recall*stress 1 10.0 1.00 10.00 2 10.0 0.00 0.00 Which of the following statements best describes the interval (2.465, 4.996)?

A) A confidence interval for the mean brainwave relative amplitude of all adult men in a similar experiment exposed to a neutral stimulus and who remember 10 pictures B) A confidence interval for the mean brainwave relative amplitude of all adult men in a similar experiment exposed to a stressful stimulus and who remember 10 pictures C) A prediction interval for the brainwave relative amplitude of one adult man in a similar experiment exposed to a neutral stimulus and who remembers 10 pictures D) A prediction interval for the brainwave relative amplitude of one adult man in a similar experiment exposed to a stressful stimulus and who remembers 10 pictures A) A confidence interval for the mean brainwave relative amplitude of all adult men in a similar experiment exposed to a neutral stimulus and who remember 10 pictures B) A confidence interval for the mean brainwave relative amplitude of all adult men in a similar experiment exposed to a stressful stimulus and who remember 10 pictures C) A prediction interval for the brainwave relative amplitude of one adult man in a similar experiment exposed to a neutral stimulus and who remembers 10 pictures D) A prediction interval for the brainwave relative amplitude of one adult man in a similar experiment exposed to a stressful stimulus and who remembers 10 pictures