# Biostatistics with R/Introduction to Biostatistics

REVIEW EXERCISES

1. Explain what is meant by descriptive statistics.

2. Explain what is meant by inferential statistics.

3. Define: (a) Statistics (b)Biostatistics (c) Variable (d)Quantitative variable (e) Qualitative variable (f)Random variable (g) Population (h)Finite population (i) Infinite population (j)Sample (k) Discrete variable (l)Continuous variable (m) Simple random sample (n)Sampling with replacement (o) Sampling without replacement

4. Define the word measurement.

5. List, describe, and compare the four measurement scales.

6. For each of the following variables, indicate whether it is quantitative or qualitative and specify the measurement scale that is employed when taking measurements on each: (a) Class standing of the members of this class relative to each other (b) Admitting diagnosis of patients admitted to a mental health clinic (c) Weights of babies born in a hospital during a year (d) Gender of babies born in a hospital during a year (e) Range of motion of elbow joint of students enrolled in a university health sciences curriculum (f) Under-arm temperature of day-old infants born in a hospital

7. For each of the following situations, answer questions a through e: (a) What is the sample in the study? (b) What is the population? (c) What is the variable of interest? (d) How many measurements were used in calculating the reported results? (e) What measurement scale was used? Situation A. A study of 300 households in a small southern town revealed that 20 percent had at least one school-age child present. Situation B. A study of 250 patients admitted to a hospital during the past year revealed that, on the average, the patients lived 15 miles from the hospital.

8. Consider the two situations given in Exercise 7. For Situation A describe how you would use a stratified random sample to collect the data. For Situation B describe how you would use systematic sampling of patient records to collect the data.