Stats ch 6
A researcher selects a sample of 25 participants from a population with a mean of 10 and a standard deviation of 5. What is the probability of selecting a sample mean that is at least two standard deviations larger than the population mean
.0228
A researcher selects a sample of 64 participants from a population with a mean of 10 and a variance of 16. What is the standard error of the mean
.5
A researcher selects a sample of size 6 from a population of size 10. How many possible samples of this size can be selected using theoretical sampling
1,000,000
A researcher randomly selects a sample of participants from a population with a variance of 4. If a researcher selects a sample of 16 participants with a mean of 12, then what is the mean and standard error for the sampling distribution of the mean
12 and .5
A researcher selects a sample of size 4 from a population of size 6. How many possible samples of this size can be selected using experimental sampling
15
A researcher selects a sample of 121 participants from a population with a mean of 32 and a standard deviation of 22. What is the standard error of the mean?
2.0
An article states that a sample of 40 participants took 12 ± 2.3 (M ± SEM) s to complete a cognitive assessment. Which value is the standard error of the mean
2.3
The following samples were selected by two researchers. Which is associated with a smaller standard error of the mean?Researcher A: n = 18, = 8, = 2.4Researcher B: n = 12, = 8, = 2.4
researcher A
In terms of characterizing samples, statistical theory was developed using a sampling strategy in which
the order of selecting participants mattersthe same participant can be selected twice in the same sampleparticipants are replaced after being sampledall of the above
The following samples were selected by two researchers. Which is associated with a smaller standard error of the mean?Researcher A: n = 25, = 5, = 7Researcher B: n = 25, = 32, = 7
they both have the same standard error
How is the standard error of the mean typically reported in a graph
using error bars
What is the central limit theorem
It explains that a sampling distribution of possible sample means is approximately normally distributed, regardless of the shape of the distribution in the population.
A researcher selects two samples of 64 participants each. In the first sample the population mean was 10 and the variance was 16. In this second sample, the population mean was 25 and the variance was 9. Which sample will be associated with a larger standard error of the mean
Sample 1
Which of the following allows researchers to use the standard normal distribution to estimate the probability of selecting sample means
The central limit theorem
A researcher randomly selects a sample of athletes and reports that their average score on a health and fitness scale is 23. Based on the characteristics of the sample mean, what does this say about the mean in the population
We expect that the population mean is equal to 23 because the sample mean is an unbiased estimator of the population mean.
A sampling distribution of the sample mean or variance is
a distribution of all sample means or sample variances that could be obtained in samples of a given size from the same population
A researcher selects a sample of 25 participants from a population with a mean of 10 and a standard deviation of 5. What is the probability of selecting a sample mean equal to at least 12
equal to the probability of selecting a sample mean that is at most equal to 8
A researcher selects a sample of 49 participants from a population with a mean of 12 and a standard deviation of 3.5. What is the probability of selecting a sample mean that is at least equal to the population mean
equal to the probability of selecting a sample mean that is at most equal to the population mean. both a and b
Which type of sampling is most often applied by researchers in the behavioral sciences
experimental sampling
It happens to be the case that the standard error of the sampling distribution of sample means
is minimal
Each of the following statements are true, except that ______. a.increasing the sample size will decrease standard errorb.the larger the standard deviation in the population, the larger the standard errorc.the larger the sample size, the larger the standard errord.the smaller the sample size, the larger the population size
the larger the sample size the larger the standard error
A distribution of all sample means or sample variances that could be obtained in samples of a given size from the same population is called
a sampling distribution
A researcher selects a sample of 49 participants from a population with a mean of 12 and a standard deviation of 3.5. What is the probability of selecting a sample mean of 13 or larger from this population
less than .03
The shape of the sampling distribution of the mean is approximately ______, whereas the shape of the sampling distribution of the variance is approximately
normal; positively skewed
Suppose you select a sample of three people from a population of four (A, B, C, D). Which of the following samples is possible using the experimental sampling strategy
persons B,C and D
What does it mean to say that the sample mean is an unbiased estimator of the population mean?
If we select a sample at random, then on average we can expect the sample mean to equal the population mean.
A researcher selects a sample of 100 participants from a population with a mean of 38 and a standard deviation of 20. About 68% of the sample means in this sampling distribution should be between a sample mean ofA) 34 and 40B) 34 and 38C) 38 and 44D) 36 and 40
36 and 40
A researcher states that a sample of 100 shoppers spend 112 ± 40 (M ± SEM) dollars on groceries each week. Which value is the standard error of the mean?
40
A researcher selects a sample of 9 participants from a population with a mean of 8 and a standard deviation of 3. About 14% of the sample means in this sampling distribution should be between a sample mean of
9 and 10
Experimental research is typically conducted using a sampling strategy in which
the same participant can never be selected twice
A researcher increases the sample size, which will
decrease the standard error
The sampling distribution of the mean and the sampling distribution of the variance (when dividing SS by n - 1)
a.are both unbiased estimators
Because the sampling distribution of sample means is normally distributed, we can use the z transformation formula to find probabilities. Which of the following gives the appropriate notation for this formula?
all of these
Regardless of the distribution of the population, the sampling distribution of sample means will be approximately normally distributed. What characteristic of the mean explains this
central limit theorem
As sample size increases, the standard error of the mean
decreases
The mean of the sampling distribution of sample means is
equal to the population mean
A researcher selects two samples of 25 participants each. In the first sample, the population mean was 32 and the variance was 8. In this second sample, the population mean was 4 and the variance was 8. Which sample will be associated with a larger standard error of the mean?
The standard error will be the same
The following samples were selected by two researchers. Which is associated with a smaller standard error of the mean?Researcher A: n = 36, = 12, = 9Researcher B: n = 36, = 12, = 6
researcher B
Two researchers select a sample for a population with a mean of 12.4 and a standard deviation of 9. Researcher A selects a sample of 30 participants. Researcher B selects a sample of 40 participants. Which sample is associated with a smaller standard error
researcher B because the sample size was larger
What values are distributed along the x-axis for a sampling distribution of the sample mean
sample means
What values are distributed along the x-axis for a sampling distribution of the sample variance
sample variances
A researcher selects from a participant pool of four males and six females. He determines that the probability of selecting two male participants is p = .16. Based on this probability, what strategy did the researcher use to sample participants
sampling with replacement
A researcher selects from a participant pool of four males and six females. He determines that the probability of selecting two female participants is p = .30. Based on this probability, what strategy did the researcher use to sample participants?
sampling without replacement
