Statistical Based Inference

Each dot represents 1 day. How many days were recorded?

• 9

• 21

• 20

• 105

Zoie completes a report by asking 70 students across campus. She found that 48% of CIAA students do not wash their hands after using the bathroom. What is the population of her survey?

• the bathroom

• CIAA students

• 48% of students

Assign each car in a dealership a number and then use a random-number table to select the cars to be inspected. 

• systematic

• random sample

• convenience

• biased sampling

Which has fatter tails?

• t-distribution

• normal distribution

• standard normal distribution

• chi-square distribution

Answer explanation

(see image)

What is the degrees of freedom of the t-distribution if its sample size is 8?

• 7

• 6

• 8

• 9

True or False. The t-distribution becomes similar to the standard normal distribution as sample size becomes larger.

• True

• False

Answer explanation

True. As n increases, the t-distribution will approach the standard normal distribution.

Fill in the blank. As the d.f. ______, the t-distribution approaches the standard normal distribution

• increases

• decreases

• stays the same

Answer explanation

Increases. The t-distribution becomes similar to the standard normal distribution as sample size becomes larger.

Which refers to the method of making decisions about the parameters of a population based on random sampling? It helps to assess the relationship between the dependent and independent variables.

• Inferential statistics

• Data collection

• Descriptive statistics

• Exploratory data analysis

Answer explanation

Statistical inference draws conclusions about a population or process from sample data. It also provides a statement of how much confidence we can place in our conclusions (Moore, et.al, 2017).

Which area of statistical inference refers to the process of estimating the value of a parameter from information obtained from a sample?

• Data analysis

• Estimation

• Test of significance

• Hypothesis Testing

Which area of statistical inference refers to the process of assessing the evidence provided by the data in favor of some claim about the population parameter?

• Hypothesis testing

• Estimation

• Test of significance

• Data analysis