Quiz 4

GER Quiz 4

1) Determine the type of the following variables
Caterogical Nominal, numerical, caterogical ordinal, numerical
Sex is nominal. Stress is categorical ordinal as the answers are ranked in catergories in a natural order (rank 1, 2, 3), where each one corresponding to varying levels of stress. It is not numerical as the answer is not a numerical value, rather it is a category.

2) The height of 1000 randomly selected NUS students...
Nature Variability and Random Error.
See slide 21. There is natural variability due to natural differences in heights of the students, and random error due to the weighing scale itself. It is not systematic, as systematic error only appears when you compare 2 different histogram with 2 different medians. Systematic error does not show up on a single histogram alone.

3. Three instruments, A, B and C...
II only
Instrument A is not free of error. While it is free of systematic error, it still has some random error.
It is possible to determine whether Instrument B or C has a smaller bias. C, as seen from the graph, has a smaller standard deviation, hence is is more reliable. See slide 21

Q4) Canabilis
We anticipate the reported fraction to be different from the actual fraction.
It is illegal in many countries

Q5) Common Core State Standards
Both I and II
According to the website
-For both policymakers and political candidates, the poll results at times say conflicting things, even if the questions were worded differently.
-(In an essay analyzing the two polls, he and his colleague Martin R. West wrote that the "two surveys are complementary, because they ask about different topics.")
-The Education Next survey polled nearly 4,100 adults, and has a margin of error of 2 percent; the PDK/Gallup poll asked 1,000 adults by phone and 3,500 adults online. PDK/Gallup’s phone survey has an error margin of 4.79 percent while the online version’s was 3.02 percent.

(From a friend)