## [answered] Biostats SDS 328M Homework 9 Part 1 - Hand work (all work m

I really need help with the whole worksheet but primarily with the problems that don't deal with R. If you could help me with the R problems that would be great. Thanks!

Biostats SDS 328M Homework 9

Part 1 ? Hand work (all work must be done by hand).

Write your answers onto one or more separate sheets of paper. Clearly mark each sheet with

Round all answers to at least 3 decimal places and assume that ?=0.05 unless otherwise noted.

1. Cellular ability to regulate homeostasis is important for normal cell functioning and can be

measured by basal calcium (Ca) pump activity (nmol/mg/hr). In a study investigating the

effect of mercury (Hg) exposure in mothers on their newborn?s cellular regulatory function,

researchers measured the mercury deposits (mg/g) in the hair of a sample of 43 mothers

along with their newborn?s basal Ca pump activity. The data are summarized below: Mean

St. Dev.

Correlation Hair Hg Level

(mg/g)

1,980.72

493.67 Basal Ca Pump

Activity (nmol/mg/hr)

3,208.05

611.35

-0.51 a. Assuming all relevant assumptions were met, calculate the linear regression equation

that predicts newborn basal Ca pump activity from maternal hair Hg level. (2pt)

b. Within the context of the problem, interpret the estimates of the slope and intercept of

the model. (1pt)

c. What proportion of the variation in newborn basal Ca pump activity can be explained by

the variation in maternal hair Hg level? (1pt)

d. If a mother had a 2,500 mg/g mercury deposits in her hair, what would you predict her

baby?s basal Ca pump activity to be? (1pt) 2. Students in a lab grew a bacterium in broth culture at three different pH levels (acidic,

neutral, basic) and across two temperatures (chilled, room temperature). Growth was

measured by optical density (cells/mL). The mean densities for each combination of

conditions are listed in the table below:

Table 1 ? Mean Bacterium Density (cells/mL)

pH

Acidic

Neutral

Basic Temperature

Chilled

Room Temp

11

16

12

23

14

21 Copyright ? 2016 Dept. of Statistics and Data Sciences, UT Austin a. Sketch an interaction plot displaying the mean density for each combination of

temperature/pH levels. Plot pH on the horizontal axis and use different lines for the

temperature levels. (2pt)

b. From your graph, does there appear to be an interaction between temperature and pH on

cell density? Why/why not? (1pt)

c. Fill in the ANOVA table below. Use either p&lt;0.05 or p&gt;0.05 in the last column. (3pt)

df

pH

Temperature

pH* Temperature

Error

Total SS MS F p-value 216.5

330.8

423.7

45 2367.1 d. Write a full conclusion to this analysis. (3pt) Part 2 ? R work (must be done in R)

Copy and paste your R code and output into a word document to submit to Canvas.

Follow these instructions to import the necessary dataset: Go to the Canvas Lab site and scroll down to the Lab 10 module. Click on ?Lab 10 Dataset,? download lab10_bodyfat.csv, and save it to your computer.

Remember: don?t use Safari to download .csv files from Canvas. Import lab10_bodyfat.csv into R and name the data frame with your UT EID. Remember to include any code you use along with your answers in your submission! 3. This dataset contains information about the size (in cm) of different body parts of a sample of

healthy adult men. You are interested in variables that can explain variation in abdomen size.

a. Does thigh size have a significant linear relationship with abdomen size? Conduct the

appropriate test and include all steps for full credit. (4pt)

b. Compared to thigh size, is hip size a better linear predictor of abdomen size? Include

the relevant statistics to support your answer. (2pt) Copyright ? 2016 Dept. of Statistics and Data Sciences, UT Austin

Solution details:
STATUS
QUALITY
Approved

This question was answered on: Sep 18, 2020

Solution~0001005679.zip (25.37 KB)

This attachment is locked

We have a ready expert answer for this paper which you can use for in-depth understanding, research editing or paraphrasing. You can buy it or order for a fresh, original and plagiarism-free copy from our tutoring website www.aceyourhomework.com (Deadline assured. Flexible pricing. TurnItIn Report provided)

STATUS

QUALITY

Approved

Sep 18, 2020

EXPERT

Tutor