Question

#12 what is the least reliable sampling method to obtain an unbiased sample?
(a) cluster sampling
(b) stratified sampling
(c) systematic sampling
(d) convenience sampling
(e) simple random sampling

#13 which type of statistical graph is most appropriate to display relative frequency
(i.e. \parts to whole\) data?
(a) histogram
(b) bar chart
(c) pie chart
(d) box plot
(e) ogive

#14 which type of graph is most appropriate to display cumulative frequency data?
(a) histogram
(b) bar chart
(c) pie chart
(d) box plot
(e) ogive

#15 what are the mandatory conditions that you need to apply the empirical rule?
(a) distribution of data values must be skewed
(b) distribution of data values must be uniform
(c) distribution of data values must be symmetric
(d) distribution of data values must be bell - shaped
(e) both (c) & (d)

Explanation:

• #12: Convenience sampling selects easily accessible subjects, leading to bias, making it least reliable for unbiased samples.
• #13: Pie charts show proportions of a whole, ideal for relative frequency ("parts to whole") data.
• #14: Ogives plot cumulative frequencies, directly displaying cumulative frequency data.
• #15: The Empirical Rule applies to bell-shaped (normal) distributions, which are symmetric; thus both (C) and (D) are required.

Answer:

D. Convenience sampling
C. Pie chart
E. Ogive
E. Both (C) & (D)