Hierarchical multiple regression, Mathematics

Assignment Help:

A group of children who lived near a lead smelter in El Paso, Texas, were identified and their blood levels of lead were measured. An exposed group of 46 children were identified who had blood-lead levels ≥ 40 μg/mL in 1972 (or for a few children in 1973). This exposed group is defined by the variable Group=2. A control group of 78 children were also identified who had blood-lead levels < 40 μg/mL in both 1972 and 1973. This group is defined by the variable Group=1. All children lived close to the lead smelter. The codebook for this case study is attached in Appendix I.

One important outcome variable studied was IQ. There were three IQ variables measured: IQV (verbal IQ), IQP (performance IQ) and IQF (full scale IQ, not sum or average of IQV and IQP). The other variables including gender (sex), age, distance from the smelter (area), blood lead values in 1972 and 1973 (LD72 and LD 73, FST2YRS (Did child live for 1st 2 years within 1 mile of the smelter) and TOTYRS (Total number of years spent within 4.1 miles of the smelter) were also investigated in the study.

(1) Generate appropriate descriptive statistics to summarise all variables between exposed and control groups; and explain the results. (Charts can be optionally used to support your analysis).

(2) Use t-tests or chi-square tests to compare the differences in age, sex, area, FST2YRS, TOTYRS between exposed and control groups. Present your hypothesis for each test and explain the results.

(3) To explore the relationship between lead exposure and the outcome variables, you need to compare the three outcome variables between exposed group and control group.  Find out if higher lead exposure has significant impacts on the scores of different IQ tests.

(4) Conduct a hierarchical multiple regression to explore factors that impact on children's blood lead level. Enter demographic variables (sex and age) in the first block, and area, FST2YRS and TOTYRS in the second block. Present and interpret your results.

(5) Summarise the major findings you obtained above and discuss the relationship between exposure and outcomes as well as the other contributing factors.


Related Discussions:- Hierarchical multiple regression

Give a definition of perimeter and area, Give a Definition of Perimeter and...

Give a Definition of Perimeter and Area? Perimeter is the distance around a flat (2-dimensional) shape. Area is the amount of space taken up by a flat (2-dimensional) shape. is

Fractions, kim had 1/2 an orange. she gave Linda 1/4 of this. What fraction...

kim had 1/2 an orange. she gave Linda 1/4 of this. What fraction of the whole orange did Linda get?

Show frequency tables, Q. Show Frequency Tables? Ans. A frequency ...

Q. Show Frequency Tables? Ans. A frequency table is used to show how often a piece of data occurs. Example: Michelle decides to keep track of the number of phone call

Domain and range of a function , Domain and range of a functio:  One of th...

Domain and range of a functio:  One of the more significant ideas regarding functions is that of the domain and range of a function. In simplest world the domain of function is th

Describe the laws of sines, Q. Describe the Laws of Sines? Ans. Up...

Q. Describe the Laws of Sines? Ans. Up to now we have dealt exclusively with right triangles.  The Law of Sines and the Law of Cosines are used to solve  oblique triangles

Probability, an insurance salesman sells policies to 5 men, all of identica...

an insurance salesman sells policies to 5 men, all of identical age in good health. the probability that a man of this particular age will be alive 20 years hence is 2/3.Find the p

..percentage, how to express 15/4 into percentage

how to express 15/4 into percentage

Solve 3 + 2 ln ( x /7+3 ) = -4 logarithm, Solve 3 + 2 ln ( x /7+3 ) = -4 . ...

Solve 3 + 2 ln ( x /7+3 ) = -4 . Solution This initial step in this problem is to get the logarithm by itself on one side of the equation  along with a coefficient of 1.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd