Exam 1 LC, Quiz Qs

to adjust for nonsampling errors, once the data are collected, you can _____ the responses

adjust

larger samples give ____ variable results as compared to smaller samples

less

variable that has an important effect on the relationship among the variables in a study, but is not one of the explanatory variables studied

lurking variable

margin of error in a confidence statement includes...

only random sampling error

population should be ____x larger than sample size

100

if the population is at least ____x larger than the sample, the population size doesn't matter in the variability of a stat

20

Ideal bias and variability

both low

an observational study cannot be used to establish cause/effect because of potential __________

confounding

purpose of the U.S. census

create election districts

a characteristic of SRS that sets it apart from other samples is that...

every sample of the same size has the same chance to be selected

who/what we're interested in being able to address as a result of the study

population

a matched pairs design can give more _____ results than a completely randomized

precise

college students decide where to live based on price and #/type of amenities; examine relationship between price and amenities, _____ will be response variable

price

what kind of errors does the margin or error account for

random sampling error

types of errors possibly present in surveys

sampling errors, random sampling error, and nonsampling error

a good sampling method has _____ bias and ______ variability

small; small

an observed event that would rarely occur by chance is ______

statistically significant

type of sample when a water company samples 20 commercial users, 500 residential users

stratified sampling

significant

unlikely to have occurred by chance if there was no difference between the placebo and treatment groups

how to reduce variability

use a larger sample size