4th Quarter Summative test Statistics and Probability

In a left-tailed test with 𝛼=0.01, the critical value of z is:

• -2.576

• -2.326

• -2.326

• -1.645

Which of the following defines the area encompassed by the values not included in the non-rejection region or also the area of the tails of the distribution?

• critical value

• level of significance

• rejection region

• level of       significance

In a right-tailed test, the rejection lies in the ________ tails of distribution.

• up

• left

• right

• down

If the level of significance decreased from 0.1 to 0.05, then the boundaries for the critical region move farther away from the center of the distribution.

• true

• false

• either true or false

• cannot be determined

Which of the following is the sketch of the normal curve if 𝑧<−1.645 𝑜𝑟 𝑧>1.645?

• 
• 
• 
• 

What is the critical value if the population variance is known, 𝑎=0.025, and it is a two-tailed test?

• 𝑧=±1.28

• 𝑧=±1.645

• 𝑧=±1.96

• 𝑧=±2.326

Given the graph of the normal curve at the right, what are the directional test of hypothesis and critical z value if 𝛼=0.01?

• two-tailed test, ±2.33

• two-tailed test, ± 2.575

• left-tailed test, −1.645

• right-tailed test, 1.645

In the given problem below, what is the rejection region?

The factory owner claimed that their bottled fruit juice has the capacity of less than an average of 280 ml. To test the claim, a group of consumers gets a sample of 80 bottles of the fruit juice, calculates the capacity, and then finds the mean capacity to be 265ml. The standard deviation is 8ml. Use 𝛼=0.05 level of significance to test the claim.

• 𝑧 < −1.645

• z < −1.28

• 𝑧 > 1.645

• 𝑧 > 1.645

Based on the given problem in no. 8, which is the appropriate rejection region?

• 
• 
• 
• 

The value that separates a rejection region from an acceptance region is called a ___________.

• Parameter

• Hypothesis

• Critical Value

• Significance level