Mar 15 review

How many degrees of freedom do you have?

σ = 1021,

μ = 181,

n = 16

• 45.25

• 4

• 16

• 15

Which of the following statements about Z and T statistics is FALSE?

• Z requires knowledge of the population standard deviation. T does not.

• T takes sample size into account. Z does not.

• Z can be used to find percentiles. T can be used to find confidence intervals.

• Both Z and T operate off a standard normal distribution.

Two populations of Howler Monkeys were sampled for different metrics of body size. The null hypothesis was that tail length would be the same in both populations. The study found tail length to differ by 2%, p = 0.065. Which of the following are true if α = 0.05?

• The null hypothesis is accepted.

• The alternative hypothesis is accepted.

• They failed to reject the null hypothesis.

• The alternative hypothesis is false.

A t-test to see if the mean weight of Colombian red howler monkeys is more than 7 kgs is a...

• One-sided, one-sample t-test.

• One-sided, two-sample t-test.

• Two-sided, one-sample t-test.

• Two-sided, two-sample t-test.

A t-test to see if the mean weight of Colombian red howler monkeys is more than the mean weight of Yucatán black howler monkeys is a...

• One-sided, one-sample t-test.

• One-sided, two-sample t-test.

• Two-sided, one-sample t-test.

• Two-sided, two-sample t-test.

A t-test to see if the mean weight of Colombian red howler monkeys is different from 7 kg is a...

• One-sided, one-sample t-test.

• One-sided, two-sample t-test.

• Two-sided, one-sample t-test.

• Two-sided, two-sample t-test.

A t-test to see if the mean weight of Colombian red howler monkeys is different than the mean weight of Yucatán black howler monkeys is a...

• One-sided, one-sample t-test.

• One-sided, two-sample t-test.

• Two-sided, one-sample t-test.

• Two-sided, two-sample t-test.

Which of the follow do you substitute for σ to calculate a confidence interval?

• s/√n

• s

• s/n

For which of these do you use reverse look-up on your T-statistic table?

• Find the degrees of freedom.

• Determine the probability that Y-bar is different from
  μ, given n

• To generate 95% confidence interval

• Determine the probability that Y-bar is greater than
  μ, given n

What is the difference between a parametric and non-parametric test?

• Parametric tests require normally distributed variables, non-parametric tests do not.

• Parametric tests operate only on continuous variables.

• Parametric tests are based on a z distribution. Non-parametric tests are based on a t distribution.