Question

Researchers collected data to examine the relationship between pollutants and preterm births in Southern California. During the study air pollution levels were measured by air quality monitoring stations. Specifically, levels of carbon monoxide were recorded in parts per million, nitrogen dioxide and ozone in parts per hundred million, and coarse particulate matter PM₁₀ in μμg/m3. Length of gestation data were collected on 143,196 births between the years 1989 and 1993, and air pollution exposure during gestation was calculated for each birth. The analysis suggested that increased ambient PM₁₀ and, to a lesser degree, CO concentrations may be associated with the occurrence of preterm births.

a. The paragraph above describes an

A. Observational Study
B. Experiment

b. The cases in this research are

A. Each year between 1989 and 1993
B. Each type of pollution measured by air quality monitoring stations
C. Each birth between 1989 and 1993
D. Air pollution exposure during gestation

c. What is the research question?

A. How can expectant mothers avoid air pollution?
B. How much air pollution is there in Southern California?
C. How prevalent was preterm birth during the years 1989 to 1993?
D. Are preterm births associated with air pollution levels?

d. What is the population of interest?

A. All air quality monitoring stations
B. All years for which air quality has been measured
C. All human babies
D. All environmental pollutants

e. What is the sample?

A. The 143,196 births
B. All air quality monitoring stations
C. The pollution measurements for the 4 pollutants
D. The years between 1989 and 1993

f. Can the findings of this study be used to establish casual relationships?

A. No, because this is an observational study
B. Yes, because air pollution is bad for human health
C. No, because this is an experiment
D. Yes, because the sample size is so large

need help no clue what i am doing wrong?

Answer 1