# Question: A number of investigations have focused on the problem of

A number of investigations have focused on the problem of assessing loads that can be manually handled in a safe manner. The article “Anthropometric, Muscle Strength, and Spinal Mobility Characteristics as Predictors in the Rating of Acceptable Loads in Parcel Sorting” (Ergonomics [1992]: 1033–1044) proposed using a regression model to relate the dependent variable y = individual’s rating of acceptable load (kg) to k = 3 independent (predictor) variables:

x1 = extent of left lateral bending (cm)

x2 = dynamic hand grip endurance (seconds)

x3 = trunk extension ratio (N/kg)

Suppose that the model equation is

and that s = 5.

a. What is the population regression function?

b. What are the values of the population regression coefficients?

d. Interpret the value of b3.

e. What is the mean rating of acceptable load when extent of left lateral bending is 25 cm, dynamic hand grip endurance is 200 seconds, and trunk extension ratio is 10 N/kg?

f. If repeated observations on rating are made on different individuals, all of whom have the values of x1, x2, and x3 specified in Part (e), in the long run approximately what percentage of ratings will be between 13.5 kg and 33.5 kg?

x1 = extent of left lateral bending (cm)

x2 = dynamic hand grip endurance (seconds)

x3 = trunk extension ratio (N/kg)

Suppose that the model equation is

and that s = 5.

a. What is the population regression function?

b. What are the values of the population regression coefficients?

d. Interpret the value of b3.

e. What is the mean rating of acceptable load when extent of left lateral bending is 25 cm, dynamic hand grip endurance is 200 seconds, and trunk extension ratio is 10 N/kg?

f. If repeated observations on rating are made on different individuals, all of whom have the values of x1, x2, and x3 specified in Part (e), in the long run approximately what percentage of ratings will be between 13.5 kg and 33.5 kg?

## Answer to relevant Questions

The article “Readability of Liquid Crystal Displays: A Response Surface” (Human Factors [1983]: 185–190) used an estimated regression equation to describe the relationship between y = error percentage for subjects ...The cotton aphid poses a threat to cotton crops in Iraq. The accompanying data on y = infestation rate (aphids/100 leaves) x1 = mean temperature (C) x2 = mean relative humidity appeared in the article “Estimation of the ...Give as much information as you can about the P-value for an upper-tailed F test in each of the following situations. a. df1 = 4, df2 = 15, F = 5.37 b. df1 = 4, df2 = 15, F = 1.90 c. df1 = 4, df2 = 15, F = 4.89 d. df1 = 3, ...The paper referenced in Exercise 15.5 described an experiment to determine if restrictive age labeling on video games increased the attractiveness of the game for boys age 12 to 13. In that exercise, the null hypothesis of ...The paper referenced in the previous exercise also gave data for 12- to 13-year-old girls. Data consistent with summary values in the paper are shown below. Do the data provide convincing evidence that the mean rating ...Post your question