In: Statistics and Probability
For problems 7-8: A popular website places opinion poll questions next to many of its news stories. A participant simply clicks their response to join the sample. One of the questions in January 2008 was “Do you plan to diet this year?” More than 30,000 people responded, with 68% saying “yes.” 7. What type of bias would this poll represent? (Explain your answer) 8. What can you conclude? a. about 68% of Americans like to diet b. the results tell us little about the population because of bias c. the sample is too small to draw a conclusion
7. What type of bias would this poll represent?
This poll represents sampling bias. For this survey, entire population under study is not covered very well, because survey is done by using only responses through website survey. We know that, all peoples do not use particular website or some peoples do not use internet or any other social media. So, responses collected by using website survey do not represent entire population of US. This type of bias is called as sampling bias. For reducing these types of biases, researchers would use different methods to cover entire population. We do not infer about entire population only based on this website survey. Also, there would be problem of non-response by using website survey.
8. What can you conclude?
b. the results tell us little about the population because of bias
Explanation: We know that the sample size is not too small to draw the conclusion. Also, we do not infer about entire population only based on website survey due to above discussed sampling bias.