BESC 3010 Final

What are the values of skewness and Kurtosis for a normal distribution?

skewness=0 Kurtosis=0

What is the symbol for standard error

sigma X bar

Imagine a sample with n=16, mean of 52 that comes from a population. SD of 12 95% CL

(46.12, 57.88)

If a test has a population mean of 140 and a standard deviation of 12 then what is the z-score for the sample of n=9 scores with a mean of 136

-1 (z-score for a sample)

What is the sample standard deviation for the following data? 2, 2, 3, 4, 4

0.80 (standard deviation for a sample formula)

If a positively skewed distribution of 132 scores with a mean of 49 and a standard deviation of 14 is standardized then the new distributions mean will be...?

1

If a distribution has a mean of 200 and a standard deviation of 40 then what is the standard error for a sample of 400 scores?

2

If a distribution has a mean of 70 and a standard deviation of 4, then what is the z-score for a sample of 64 scores with a mean of 71?

2

If a population has a mean of 40 and a standard deviation of 9, what would the z-score be for a sample of 9 people with a mean of 46?

2

If a population has a mean of 60 and a standard deviation of a, what is the z-score for a sample of 144 people with an average of 62?

3

If the population mean for a distribution is 150 and the standard deviation is 10, then what is the z-score for a sample of 100 people with an average score of 153

3

What is the point estimate for the population mean if the sample mean is 55, the population standard deviation is 15 and the sample size is 25?

55

Imagine two studies that are identical in every respect except their p-values and effect sizes. Sample A has a sample size of n=60 and a p-value of .02. Sample B has a sample size of n=60 and a p-value of .08. Which sample likely had the larger effect size?

Sample A

When a sample comes randomly from the general population but that sample's mean is nonetheless significantly different from the populations then...

a Type I error has occurred

When a distribution of raw scores is converted to z-scores, the shape of the distributions...

approaches a normal distribution

In a positively skewed distribution the extreme scores are_______

at the high end

When the range of confidence for a confidence interval becomes lower- from 95% to 90%, for example- then the confidence interval will...

become narrower

What is the range for this data set? 5, 3, 7+, 1, 4

cannot be calculated

Imagine that a researcher is interested in whether students who receive an experimental teaching method have have higher standard test scores than the national average. What would be an appropriate alternate hypothesis for a one tailed or directional z-test for this test?

experimental students average> national average

Assuming that the null hypothesis is actually false, then what is the easiest way to make sure that it will be rejected?

increase n

What is the minimum level of measurement needed to calculate the mean?

interval

A histogram is appropriate when the data is...

interval or ratio

In a one-tailed or directional test for a one-sample z-test, if the observed value of z is greater than the critical value of z, then the null hypothesis...

is rejected

Which of the following is a defining characteristic of experiments?

manipulation

In a positively skewed distribution, which measure will generally have the highest value?

mean

Which measure of central tendency is MOST influenced by outliers?

mean

Which measure of central tendency works best of negatively skewed distributions?

median

A bell curve (i.e., a normal distribution) is...

mesokurtic

In a negatively skewed distribution which measure will generally have the highest value?

mode

If a person's employment is coded as Unemployed=0 or Employed=1, then that variable is at the _______ level of measurement

nominal

If a person's sex is recorded as "Male" or "Female," then that variable is at the _____ level of measurement.

nominal

What is the lowest level of measurement needed to calculate the mode?

nominal

As the size of samples (n) in a sampling distribution increases, the shape of that distribution becomes more...

normal

If a distribution of raw scores is completely uniform then, given a sufficiently large n, the sampling distribution of means for that distribution will be...

normal

According to the central limit theorem when all possible samples of a sufficient size are taken from a bimodal population and their names are charted, that distribution of means will be...

normally distributed

As n increases, the point estimate for the mean will...

not change

Which measure requires a degrees of freedom calculation?

population variance

A distribution such as income that has most of the people at the bottom or middle but a few extremely high scores is referred to as

positively skewed

The amount of time a person spends on social media each week is a _______ variable.

ratio

If a researcher is using a critical value of +- 1.96 for a z-test and gets an observed z of -2.73, then the researcher should...

reject the null hypothesis

As the mean for a sample becomes greater, the width of the corresponding confidence interval will

stay the same

According to the central limit theorem the mean of the sampling distribution of means will equal...

the mean of the original population

If you conduct a one-sample z-test, you would test...

the null hypothesis of no difference between the groups mean and the population mean

If a researcher is using alpha=.05 and gets a p-value for the z-test of p=.02, then...

the results are unlikely to occur by chance if the null hypothesis is true

A point estimate for the population mean is based on...

the sample mean

When calculating an effect size for the z-test

the sample size is irrelevant

When the distribution of all possible samples of a given size are taken from a population and their means are charted that distribution is known as...

the sampling distribution of means

The standard error is...

the standard deviation of a sampling distribution

If a person were to create a sampling distribution for sample standard deviations then the mean of that distribution would be equal to...

the standard deviation of the original population

If the formula for the population standard deviation were used with sample data, then result would be...

too small

If scores in a data set are very different from each other then compared to when they are more similar to each other the standard deviation

will be low