Inferential Statistics - Chapter 2

Question 1

When do I actually use z-test and t-test?

Answer 1

Z-test:
Sample Size - Large (n>30)
Population Standard
Deviation - Known

T-test:
Sample size - Small ((n≤30)
Population Standard Deviation - Unknown (use sample
standard deviation)

Question 2

What is t-test?

Answer 2

The t
test is a statistical method used to compare the means of groups and determine if
the differences are statistically significant.
These are tests used to determine if there are significant differences between the means of
two groups.

Question 3

What is the relationship between the t-statistic, p-value and the significance level?

Answer 3

T-statistic determines the p-value:

p value < = significance level (Reject H0)

p value > Fail to reject null hypothesis

Question 4

What are the types of t-tests?

Answer 4

-One sample t-test
-Independent sample t-test
-Paired t-test

Question 5

What is a one sample t test?

Answer 5

Compare sample mean to a known population mean: Null hypothesis(H0 = means is equal to the value)

Question 6

What is a independent sample t-test?

Answer 6

Compares mean of two independent groups. Null hypothesis is means of two groups are equal

Question 7

What is the paird sample t-test?

Answer 7

Compares means of same group before and after intervention. (H0 = mean difference between paired observations is zero)