Sampling Methods
Order the population and then select from it at regular intervals.
What is systematic sampling?
In a __________ probability distribution, every outcome has the same chance of happening.
What is uniform?
A set of data with a mean of 45 and a standard deviation of 8.3 is normally distributed. What value is one standard deviation above the mean?
What is 53.3?
A confidence interval reflects uncertainty due to using a ________ instead of the whole population.
What is a sample?
If the p value is LESS than alpha, you should REJECT the __________ hypothesis.
What is null?
A type of survey that divides a population into groups, like their age, and then picks people randomly from a particular group for the survey or experiment is what kind of sampling?
What is stratified sampling?
A __________ distribution describes how often something happens in a fixed amount of time or space when it happens randomly but at a steady average rate.
What is Poisson?
A machine is used to put bolts into boxes. It does so such that the actual number of bolts in a box is normally distributed with a mean of 106 and a standard deviation of 2. What percentage of boxes contain more than 106 bolts?
What is 50%?
As the confidence level increases, the confidence interval becomes _______.
What is wider?
H0: μ < 20
Ha: μ > 20
Is this a lower-tail or upper-tail test?
What is upper?
A type of survey that divides a population into subpopulations, like their ZIP code, and then picks people randomly from a particular subgroup for the survey or experiment is what kind of sampling?
What is cluster sampling?
A __________ experiment consists of a sequence of n identical, independent trials with two outcomes, success and failure, are possible on each trial. The probability of a success does not change from trial to trial.
What is binomial?
Normal, uniform, poisson, binomial: Which probability distribution is symmetric around its mean?
What is normal?
True or False:
Changing the alpha level can change whether you reject the null hypothesis in favor of the alternative, even when the p-value stays the same.
TRUE.
A type of survey where the person most knowledgeable on the subject of the study selects elements of the population that he or she feels are most representative of the population is using what kind of sampling?
What is judgement sampling?
A __________ probability distribution describes data that form a bell-shaped curve, where most values cluster around the average, and extremely high or low values are less common the farther you go from the center.
What is normal?
To find an expected value, you multiply each possible outcome by its ___________, then ___________ all those products.
1. probability
2. add
A confidence interval is the sample mean plus and minus the __________.
What is margin of error?
How is the universe ordered?
The universe is ordered according to perfect mathematical laws.
A __________ is a number from your sample that is used to estimate an unknown value in the population.
What is a point estimate?
Fill each blank with: Normal, Poisson, Binomial, Uniform:
The time (between 0 and 10 seconds) that a computer waits before selecting a random number: ___________
The number of customers who arrive at a coffee shop in a 15-minute interval: ___________
Whether a seed sprouts or does not sprout, repeated across 20 seeds: ___________
Test scores on a large exam where most students score near the average: ___________
1. Uniform
2. Poisson
3. Binomial
4. Normal
rxy = sxy/(sx * sy)
This is the formula for a __________.
What is a correlation?
You could get a smaller standard deviation (and therefore a narrower confidence interval) by increasing the __________.
What is sample size?
What is statistics?
Statistics is the systematic, mathematical collection and analysis of "actual events" in large quantities for the purposes of finding useful, practical insights.