Description

1.    Load the file Lab Week 7 - NHANES subset.csv  into Excel and R.

2.    Inspect the NHANES subset (n=1000) by computing descriptive statistics on SBP characterizing the cohort. Functions: summary, mean, median, sd, standard error, 25th and 75th percentile, IQR in Excel and R. Compare the values.

3.    Build histograms of SBP indicating mean and 1 SD (R). Try three different approaches (differing in the range of the bins).

4.    Compare the standard deviation and the standard error of SBP. What do you notice?

5.    Draw 3 random samples (n=100) and build three objects – how do standard deviation and standard error of SBP compare to each other and to the overall population. How do histograms of SBP compare?

6.    What interval contains 95% of all SBP values in R and Excel?

Grading weights: Q1 (5%); Q2 (25%), Q3 (15%), Q4 (15%), Q5 (20%) and Q6 (10%); Layout and code documenting (10%).

Deliverables: This word document with answers, pdf for figures, excel file if applicable and copy/pasted R workflow (left lower quadrant) in a *.txt file.

Point scheme:

7.    5 points

8.    25 points

1.    mean, median, sd, standard error, 25thand 75th percentile, IQR (3 points each)

2.    Excel and R comparison (4 points)

9.    15 points

1.    Histogram (5pt)

2.    Histogram with means and SD (5pt)

3.    3 with diff breaks (5pts)

10. 15 points

1.    Comparison and reasonable explanation of difference

11. 20 points

1.    Creation of 3 samples (5 pts)

2.    Compassion of sd and se (10 pts)

3.    Comparison histograms (5pts)

12. 10 pts

1.    Interval bounds (5 pts)

2.    In R and Excel (5 pts)

13. 10 pts

1.    Layout and code documenting (10 pts)

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