**Quiz 4: Inferential**

**Score 10 out of 10**

The WPC Sports Company has noted that the size of individual "customer order" is normally distributed with a mean of $100 and a standard deviation of $12. If a soccer team of 16 players were to make the next batch of orders, what would be the standard error of the mean?

Group of answer choices

- 3.00
- 3.46
- 4.00
- 10.00

When sample size increases

Group of answer choices

- Standard deviation of the sample mean increases
- Confidence interval increases
- Confidence interval remains the same
- Confidence interval decreases

Which of the following is a Type-I error?

Group of answer choices

- The null hypothesis is actually true, but the hypothesis test incorrectly rejects it.
- The null hypothesis is actually true, and the hypothesis test correctly fails to reject it.
- The null hypothesis is actually false, but the test incorrectly fails to reject it.
- The null hypothesis is actually false, and the test correctly rejects it.

What is the confidence level when the level of significance is 0.07?

Group of answer choices

- 0.970
- 0.930
- 7%
- 0.093

**Question 5 1 pts**

Which of the following is a continuous random variable?

Group of answer choices

- The number of new hires in a year
- The number bounced check from a bank
- The time to complete a specific task
- The outcomes of rolling two dice

Which of the following is a difference between the t-distribution and the standard normal (z) distribution?

Group of answer choices

- The standard normal distributions' confidence levels are wider than those of the t-distribution
- The t-distribution cannot be calculated without a known standard deviation, while the standard normal distribution can be.
- The t-distribution has a larger variance than the standard normal distribution
- The standard normal distribution is dependent on parameters like degree of freedom, while t-distribution is not.

The central limit theorem states that even if the population is not normally distributed, the

Group of answer choices

- Mean of the population can be calculated without using samples
- Standard error of the mean will not vary from the population mean
- distribution of the sample mean will still be normal when the sample size is large
- Sampling distribution of the mean will vary from the sample to sample

**Question 8 1 pts**

Which of the following proposition describes an existing theory or belief?

Group of answer choices

- Null hypothesis
- Proportion
- Alternative hypothesis
- Standard deviation

In order to reject the null hypothesis, the p-value must be less than the

Group of answer choices

- Variance
- Alpha
- Degrees of freedom
- Standard deviation

You are collecting data via an online survey to improve education standard at ASU. Which of the following methods will not result in data collection bias?

Group of answer choices

- Those with an interest in your mission are the ones to participate in the survey
- Anonymously data collection by hiding ASU brand in the survey question.
- Polls are completed only by visitors to the site
- Some individuals are less likely to participate because they have strong opinions against ASU education standard.