Take this Quiz: Data 1 — percentages, spread and what a sample proves | Zestly

Question 1

A store sells a laptop for 800 dollars. During a sale, the price is reduced by 20 percent. What is the new price of the laptop?

Accepted Answer

640 dollars

Answer

600 dollars

Answer

780 dollars

Answer

960 dollars

Question 2

In a city, the unemployment rate rose from 5 percent to 7 percent over one year. By what percent did the unemployment rate increase?

Accepted Answer

40 percent

Answer

2 percent

Answer

28.6 percent

Answer

140 percent

Question 3

A researcher conducts an observational study on 500 office workers and finds that those who drink more than three cups of coffee per day report higher productivity levels. Which of the following is a valid conclusion?

Accepted Answer

There is an association between coffee consumption and reported productivity.

Answer

Drinking more than three cups of coffee causes higher productivity.

Answer

The results can be generalized to all people in the country.

Answer

Coffee consumption is the primary factor determining worker productivity.

Question 4

A data set consists of the values: 10, 12, 12, 14, 15, 16, 100. Which measure of central tendency is most affected by the inclusion of the value 100?

Answer

The mean

Answer

The median

Answer

The range

Answer

The mode

Question 5

A survey of 1,000 randomly selected high school students shows that 60 percent prefer online learning, with a margin of error of 3 percent. Which of the following is a valid interpretation?

Answer

Exactly 60 percent of all high school students prefer online learning.

Answer

It is plausible that between 57 percent and 63 percent of all high school students prefer online learning.

Answer

The margin of error will decrease if the sample size is reduced.

Answer

The survey proves that online learning is superior to in-person learning.

Question 6

A two-way table categorizes 200 people by their exercise habits (Regular, Occasional, None) and their sleep quality (Good, Poor). There are 80 people who exercise regularly, and 30 of those report good sleep. What is the probability that a person chosen at random from the 'Regular' exercise group reports good sleep?

Answer

0.15

Answer

0.30

Answer

0.375

Answer

0.60

Question 7

If a line of best fit for a scatterplot has a negative slope, what does this indicate about the relationship between the two variables?

Answer

As one variable increases, the other increases.

Answer

As one variable increases, the other decreases.

Answer

There is no relationship between the variables.

Answer

The variables are perfectly correlated.