How can you decrease the variability in a sample poll?
A. Increase the sample size
B. Decrease the sample size
C. Increase the bias
D. Decrease the bias
E. None of the above
How can you decrease the variability in a sample poll? A. Increase the sample size B....
(05.01 LC) A polling company has decided to increase the size of its random sample of voters from about 2,000 people to about 4,500 people right before an election. A poll was designed to estimate the proportion of voters who favor a new law to set an 11 p.m. curfew for teenagers. What is the effect of this increase? (4 points) a To reduce the bias of the estimate b To increase the bias of the estimate c To reduce...
Select which of these increase power. Increase Alpha Decrease variability in data. Decrease N Increase N Decrease Alpha Increase Variability in data. Increase Effect Size Decrease Effect Size
Question 12 Which of the following would decrease the sample size? a. Decrease noncoverage error b. Increase the variance C. Lower the confidence level d. Decrease the population size e. Tighten the margin of error (make it smaller)
In a population proportion study, you can decrease the sample size by: decreasing alpha conducting a pilot study decreasing E assuming p-hat to be 0.25
Identify the consequences (i.e., increase, decrease, or none) that the following procedures are likely to have on BOTH bias and sampling error in an observational study. Select both that apply. a. Planning for data loss. Bias: sampling error: b. Taking measurements of the subjects while unaware of which subjects belong to which group. Bias: sampling error: c. Including only one sex and age group in the study. Bias: sampling error: d. Adjusting for body size using analysis of covariance. Bias:...
Identify the consequence (i.e. increase, decrease, or none) that the following procedures are likely to to have on both bias and sampling error in an experimental study. 1) Increasing sample size? Bias: Sampling error: 2) Assigning treatment to subjects alphabetically, not randomly? Bias: Sampling error: 3) Applying every treatment to every experimental unit in random order? Bias: Sampling error: 4) Testing only one treatment group, without a control group? Bias: Sampling error:
. Discuss how the mean difference, group variability, and sample size are related to statistical significance of the t-statistic.
4. Although the sample mean provides a good estimate of its population mean, sample variability tends to be biased. a. Explain what is meant by “biased.” b. How is sample variability biased? (Is it too large or too small?) c. How is this bias corrected in the formula for sample variance and sample standard deviation?
. Bird species may decrease egg size and increase clutch size, increase egg size and decrease clutch size, or decrease egg and clutch size. Describe the advantages and disadvantages of each strategy. Is one strategy better than any other? Why or why not? B) State Lack’s Hypothesis and describe why it is short-sighted
Which of the following is NOT a way to reduce random error? Increase sample size Change study design Randomization Improve instrumentation Ensure representativeness True/False: Random errors are more serious for the validity of a study than systematic errors. A group of women with a family history of breast cancer enroll themselves into a study that aims to reduce incidence of breast cancer. This is an example of what type of bias? Surveillance bias Nonresponse bias Recall bias Prevarication bias Misclassification...