Answer:
6108795
Step-by-step explanation:
To obtain the number of ways the committee can be selected :
4 teachers from the 12 teachers available and 3 students from the 43 students available
Using combinatorics :
12C4 * 43C3
recall :
nCr = n! ÷ (n - r)!r!
Using calculator :
12C4 = 495
43C3 = 12341
12C4 * 43C3
495 * 12341
= 6108795
Answer:
B. The observational study is a cross-sectional study because information is collected at a specific point in time.
Step-by-step explanation:
1) There are three types of Observational Studies: Case-control, cross-sectional and Cohort.
2) Since the researchers collected information from those 1800 adults at a certain time, then we can call it a cross-sectional study. It does not provide solid results since the research was not done over a period to collect further information. We don't know, for example, much more than what that association deeply mean.
3) If we wonder more, then the researchers would have to track those adults over a given period, i.e. a Cohort would be necessary.
4) Moreover, it's not "retrospective" for virtually every question, always makes us look back somehow, and it does not categorize a kind of observational study.
