Crime Statistics

For a Z score of zero, what is the proportion of area between the mean and the z-score?

0.0

What is the Z score associated with a 90% confidence level?

1.65

What is the Z score associated with a 99% confidence level?

2.58

What proportion of respondents are 2 standard deviations above the mean?

47.73

Using the normal distribution, we know that __________% of all random sample means will fall within ±1.96 standard errors of the true population mean.

95

A Z score of 1.96 is associated with which confidence level?

95%

What percentage of the area under the normal curve falls between ±2 standard deviations?

95.46

A probability of getting into a bar without paying a cover fee depends on who the bouncer is. This would be an example of what type of event:

Dependent event

There are two ways to calculate the standard error of the mean. In one of them, the standard error of the mean is calculated using which two quantities?

Population standard deviation and sample size

characteristic of a probability

Probabilities reflect the chance of an outcome occurring over many repeated events

Which two quantities are needed to estimate the standard error of the proportions?

Sample proportion and sample size

Interpret a probability of 0.05

The outcome is very unlikely

illustrates estimation

The percentage of Americans who favor gay marriage as approximated by the Gallup Poll

The standard error is also known as

The standard deviation of the sampling distribution

Interpret a probability of 0.5

There is a 50% chance that the outcome will occur

According to the Central Limit Theorem, if the sample size is larger enough, the sampling distribution of the mean is

approximately normal

The normal distribution is a __________ and __________ symmetrical distribution with the mean, the median, and the mode all coinciding at its peak and with the frequencies gradually decreasing at both ends of the curve.

bell shaped; theoretical

If all possible random samples of size N are drawn from a population with a mean of μY and a standard deviation of óy, then as N becomes larger, the sampling distribution of sample means becomes approximately normal with a mean of μӯ and a standard deviation of ó?. This statement is known as the...

central limit theorem

Ranges of values within which the population parameter may fall are called

confidence intervals

Widening the confidence interval from 95% to 99% increases the __________but decreases the __________.

confidence; precision

As the sample size gets bigger, the confidence interval

gets smaller

As the sample size gets bigger, the standard error

gets smaller

The normal distribution is central to the theory of __________ statistics

inferential

If the value of the standard error increases, what happens to the confidence interval?

it becomes wider

Confidence intervals are usually constructed for which statistic?

mean

A group that includes all the cases in which a researcher is interested is referred to as a

population

The actual percentage of Americans who support gay marriage is an example of a(n)

population parameter

Parameters are associated with __________; whereas, statistics are associated with __________.

populations; samples

A relatively small subset from a group that includes all of the cases that a researcher is interested is referred to as a

sample

If we are calculating the proportion of cases between a raw score and the mean, which of the following information is NOT necessary:

sample size

Because population parameters are typically unknown, we use the __________to estimate the value of the standard error.

sample standard deviation

If we are calculating the proportion of cases between a sample mean and the population mean, which of the following information is NOT necessary:

sample standard deviation

A point estimate is an estimate where a

sample statistic is used to estimate a range of possible values of a population parameter

When we calculate a confidence interval around a point estimate, the point estimate is a _______ and is an estimate of a ________.

sample statistic; population parameter

__________ is necessary because researchers in the social sciences almost never have enough resources to collect information about the entire set of subjects of interest to them.

sampling

A theoretical probability distribution of all possible sample values for the statistics in which we are interested in is referred to as a

sampling distribution

The likelihood that a specified interval will contain the population parameter is referred to as

the confidence level

True or False: Flipping a coin is an example of an independent event.

true

The number of standard deviations that a given raw score is above or below the mean is referred to as a

z score

the notation for the population mean

μy

true about the relationship between the population mean and the mean of the sampling distribution

μӯ = μY

Which of the following is NOT a statistic? p, ӯ, π, SY

π

Which of the following is NOT a parameter? μY, ӯ, π, σy

ӯ

the notation for the sample mean

ӯ

As the sample size gets bigger, the confidence level

does not change

true or false: If our population distribution is skewed our sample distribution will be skewed

false

True or False: If the average test score for a class is 82, and I was interested in the proportion of students who scored below a 75, I would calculate a Z score for 75 and then find the associated proportion in Column B of the Z table.

false, I would want to look at Column C of the Z table because I am interested in those who scored below a 75.

true or false: If our population distribution is skewed and our sample distribution is skewed, our sampling distribution will be skewed.

false, If the sample size is big enough, the sampling distribution will be normally distributed even if the population and sample distributions are skewed.

true or false: The sampling distribution is always normally distributed

false, the sampling distribution becomes more normally distributed as the sample size gets bigger.