Answer the Following questions
Researchers often choose to reject the null hypothesis when there is less than a 5% likelihood of observing a given pattern in the data if the null hypothesis is true. They select 5% because
It’s a rule handed down by Isaac Newton
It’s the established scientific norm
It’s the absolute best way of establishing the truth
What’s the trade-off between certainty and confidence intervals?
If you want to be more certain of your estimate, your confidence interval will be smaller
If you want to be more certain of your estimate, there must not be a confidence interval
If you want to be more certain of your estimate, your confidence interval will be larger
Which of these polls might suffer from selection bias?
A survey of Rutgers students that randomly selects students from the Dean’s registry of all students
A survey of Rutgers Sociology students that randomly selects students enrolled in a Sociology course this year
A survey of Rutgers students that randomly selects fans attending a Rutgers football game.When your sample is below ____ observations, you should check closely for outliers.
a. 15
b. 30
c. 45
d. 100
The t-distribution, relative to the normal distribution, has tails that are:
a. fatter
b. narrower
c. cooler
The degrees of freedom in the t-distribution determines
a. the total probability under the curve
b. the size of your sample
c. the contours of the bell shape
With a sample of 35 observations, what degrees of freedom would we have?
As the degrees of freedom increase, the t-distribution…
a. becomes indistinguishable from the normal distribution
b. gets wider
c. stops working
If your sample size is 10 and you want to calculate a 90% confidence interval, what is your critical t-value?
If your sample size is 20 and you want to calculate a 95% confidence interval, what is your critical t-value?
If your sample size is 30 and you want to calculate a 99% confidence interval, what is your critical t-value?
The average height of 507 adults is 171.1 cm with a standard deviation of 9.4 cm. What is the standard error?
If you wanted to create a 95% confidence interval for the mean from the previous question, what would the critical t-value be?
