Blatchley Chapter 10 Quiz

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Which of the following is true about William Gosset's contribution to statistics?

He solved the problem of small samples and unknown standard deviations

He solved the problem of large samples and unknown standard deviations

He solved the problem of unknown population means and small samples

He solved the problem of unknown population means and large samples

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The Student's t-test gives you the t-statistic, which is:

A descriptive statistic

An inferential statistic

A type of alpha level

None of the above

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The Student's t-test allows you to:

Compare two sample means

Compare a sample mean and a population standard deviation

Compare two population means

Compare a population mean and a sample standard deviation

. What is a common feature of both the t-test and the z-test?

Both produce a statistic that is a ratio

Both have a distribution that is positively skewed

Both require knowledge of the population standard deviation

Both are robust to poorly-designed experiments

. The numerator of the t-test formula is a value that describes...

The difference between two sample means

The difference between two population means

The difference between a sample mean and the standard error of the mean

The difference between a population mean and the population standard deviation

. In a t-test, the symbol s represents...

Sample standard deviation

Sample variance

Population variance

Population standard deviation

. In a t-test, the sample standard deviation is found by...

Dividing the sample variance by n-1 and taking the square root of this value

Dividing the sample variance by n and taking the square root of this value

Dividing the population variance by n and taking the square root of this value

Dividing the population variance by n-1 and taking the square root of this value

. Which of the following information is/are needed to find the sample standard deviation in a t-test?

Sample size only

Deviation scores only

A & B

None of the above

. In a t-test, the standard error of the mean is found by...

Dividing the sample standard deviation by the sample size

Dividing the sample standard deviation by the square root of the sample size

Dividing the square root of the sample standard deviation by the sample size

Dividing the square root sample standard deviation by the square root of the sample size

. The standard error of the mean obtained in a t-test is always...

Equal to the square root of the sample variance

A positive value

An overestimation of the population standard deviation

A large value for sample sizes that are very big

. The degrees of freedom of a test are usually denoted by the symbol:

df

Σ

s

Ï

. The degrees of freedom of a one-sample t-test...

Is equal to the sample size

Is equal to the sample size minus 1

Is equal to the alpha level minus 1

Is equal to the alpha level

. If the sample sizes of both groups an independent samples t-test is 15, then the degrees of freedom of the test is:

13

14

15

16

. Which of the following is true about the different aspects of a t-test?

The degrees of freedom of a test are not influenced by the sample size.

The p-value of a t-test is not influenced by the degrees of freedom.

The alpha level of a t-test is not influenced by the degrees of freedom.

The t-statistic is not influenced by the sample size.

. Given that the sample standard deviation of a test is 9, the sample size is 100 and the sample mean is 15, what is the standard error of the mean?

0.6

0.9

1.5

13.5

. The independent samples t-test is also known as the...

Z-test

Twin samples t-test

Two-sample t-test

Dependent samples t-test

. Which of the following is true about making conclusions using the t-statistic?

When the t-statistic is larger than the critical t for a one-tailed hypothesis, you must always reject the null hypothesis.

When the t-statistic is smaller than the critical t for a two-tailed hypothesis, you must always reject the null hypothesis.

When the t-statistic is smaller than the alpha level for a two-tailed hypothesis, you must always reject the null hypothesis.

When the t-statistic is larger than the alpha level for a two-tailed hypothesis, you must always reject the null hypothesis.

. Which of the following statements about the t-test is true?

The t-test allows you to make inferences about whether two sample means are significantly different.

The t-test allows you to make inferences about whether two population means are significantly different.

The t-test allows you to make inferences about whether two sources of population variability are significantly different.

The t-test allows you to make inferences about whether two sources of sample variability are significantly different.

. The t-test is a _____________ test that ______________________.

Parametric; makes several assumptions about the nature of the underlying population

Non-parametric; makes several assumptions about the nature of the underlying population

Parametric; does not make several assumptions about the nature of the underlying population

Non-parametric; does not make several assumptions about the nature of the underlying population

. Which of the following is an assumption of the independent samples t-test?

The underlying population distribution has to be perfectly normal

Both groups being compared have to be equal sizes

Both groups being compared have to be dependent on each other

The dependent variable distributions are reasonably normally distributed

. Another term for a dependent samples t-test is:

Repeated measures

Matched pairs

Natural pairs

All of the above

. Which of the following is true about a dependent samples t-test?

The variability of two groups are dependent.

The mean of two groups are dependent.

The two groups have to consist of genetically identical twins.

None of the above.

. Which of the following statements is true with regards to the independent samples t-test and a dependent samples t-test, assuming all things equal?

You are more likely to detect an effect with an independent samples t-test than a dependent samples t-test.

You are more likely to detect an effect with a dependent samples t-test than an independent samples t-test.

You are equally likely to detect an effect with a dependent samples t-test as with an independent samples t-test.

There is no systematic way to tell if you would be more likely to detect an effect with either test.

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Kylie is studying the effects of verbal praise on children's moral and social development. She recruits ten pairs of twins and assigns a child from each pair to be in a "high praise" condition and the other child to be in a "normal praise" condition. In the "high" praise condition, the child is praised every minute as they solve a mathematical problem. In the "normal praise" condition, the child is given positive feedback only after they have solved the problem. At the end of the task, Kylie measures the altruism level of each child by asking how much of their allowance would they like to donate to a charity. What test should Kylie use to examine her data?

One-sample t-test

Z-test

Independent samples t-test

Dependent samples t-test

. If a scientist has a repeated measures design, but uses an independent samples t-test to analyze the data instead of a dependent samples t-test, which of the following is true?

The scientist would be more likely to find a significant effect that is real.

The scientist would be more likely to commit Type I error.

The scientist would be more likely to commit Type II error.

None of the above.

Blatchley Chapter 10 Quiz

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