Homework 1 Answers

BSTA 512/612

Modified

January 8, 2026

Answers are not necessarily complete! This is just meant to serve as a check if you are stuck.

Directions

This document provides the solutions (final answers) for Homework 1. You may use this to double-check your final numbers and conclusions. This document does not contain the code or derivations required to arrive at the answer.

Questions

The following questions were adapted from this textbook.

Question 1

Part a

Answer: 0.6306

Part b

Answer: 11.689

Question 2

Part a

Answer:

Part b

Answer: .

Part c

Answer: (69.49, 70.51)

Question 3

Answer: fail to reject

Question 4

Answer:

Question 5

Answer: Any function from dplyr not discussed in class (e.g., arrange, slice, distinct, sample_n) is acceptable.

Question 6

Part a

Answer:

[1] "AGE"      "DRYWGT"   "LOGDRYWG"

Part b

Answer:

Part c

Answer:

  1. \(\widehat{\text{Dry weight}} = -1.885 + 0.235 \cdot Age\)

  2. \(\widehat{\log_{10}(\text{Dry weight})} = -2.689 + 0.196 \cdot Age\)

OR

  1. \(\widehat{Y} = -1.885 + 0.235 \cdot X\)

  2. \(\widehat{Z} = -2.689 + 0.196 \cdot X\)

Part d

Answer:

Part e

Answer:

  • Slope: 0.196 (95% CI: 0.185, 0.207)
  • Intercept: -2.689 (95% CI: -2.809, -2.569)

Part f

Answer:

  • Log-scale: -1.122

Question 7

Part a

Answer: weights

Part b

Answer:

Part c

Answer: No

Question 8

Answer: