Instructions: Go to the following site and answer each of the questions below. h
ID: 2935935 • Letter: I
Question
Instructions: Go to the following site and answer each of the questions below. https://edsource.org/2015/national-poll-shows-most-oppose-common-core-standards/85212 1) Consider the 47th annual Phi Delta Kappa/Gallup Poll of the Public's Attitudes Towara the Public Schools. a. What was the sample size of this poll b. What type of sample was taken? c. Was the sample random? How do you know? d. What was the population of interest? e. Was the sample biased in any way? If so, give an example. f. Do you feel as if this sample is representative of the population that the poll is sampling from? g. Based on your answers to parts (a-f) how confident are you in the results of the poll?Explanation / Answer
a) phone interviews - 1000 and internet survey - 3499
Total sample size was 4499
b) sample was SRS. Simple Random Sampling of adults.
c)
All the states of USA would have been included (since it was said it is a national poll, but no explicit indication that interviews were taken from all the states were taken)
Most of the ethnicities would have been included (but no explicit indication that all ethnicities were included. It only said there were opinions of whites, blacks, Hispanics)
Since there were no explicit indication of "stratas"(groups) not included, we can say it is SRS.
d)
The population of interes is the parents population.
Because the poll was all about the public attitude about the schools, it should be done among the parents.
There was an indication that it was done over "adults' (but no explicit words statting that it was done on parents)
e)
Assumng nationwide the proportions of white, black, hispanics and others will be different. In particular, whites will have a good majority over other ethnicities, it can be said that the poll might be biased towards whites. It the proportion of whites in sample are not in tune with the national proportion of whites, then there might be a bias.
For simplicity, say the national proportion is 40% whites, 20% blacks, 15% hispanics, 25% others.
The poll has to have 40% of 4500 (1800 approx whites), let us say if it had only 1200 whites then it might be a bias, or if it had 2500 whites then it might be a bias.