Estimating Population

At a farm there were 7 cows for every 2 horses. If there was 21 cows estimate how many horses there would be?

• 9

• 3

• 6

• 14

A park ranger caught 6 rattlesnakes and marked them. The ranger observed 14 snakes in total. She later recaptured 2 rattlesnakes that were marked. Estimate the

population size.

• 7

• 42

• 12

• 49

_______ is the entire group of objects or individuals considered for a survey.

• Sample

• Population

• Random Sample

• Quartile

If you increase the size of your sample, the Margin of Error will . . . .

• increase

• decrease

• stay the same

Yadira wanted to estimate the mean number of words per page in a 180-page book she is reading. Which if these sampling methods gives the best estimate of the mean word count per page in the book?

• Count the words on one randomly chosen page.

• Calculate the mean word count for a sample consisting of the pages with pictures.

• Calculate the mean word count for a sample of 20 pages selected by choosing every 9th page.

• Calculate the mean word count for a sample consisting of the 10 pages that appear to have the most words.

Identify the Sample: The Huddle House wants to know if their customers buy dessert when they eat out. As people leave the restaurant one evening, 20 people are surveyed at random. Eight people say they usually order dessert when they eat out. The manager at Huddle House concluded that most customers do not order dessert. What is the SAMPLE in this scenario?

• 20 customers from Huddle House

• All customers from Huddle House that evening

• 8 customers from Huddle House

• The employees from Huddle House

Identify the confidence interval used in the figure below if each shaded area is equal to 0.05.

• 90%

• 95%

• 98%

• 99%

Answer explanation

The confidence interval used in the figure is 90% because each shaded area represents 0.05, totaling 0.1 for both sides, leaving 0.9 or 90% for the interval.

Find the value of z_c for a 90% confidence interval.

• -1.96 

• 1.645

• 1.440

• -1.598

A recent study of 750 Internet users in Europe found that 35% of Internet users were women. What is the 95% confidence interval of the true proportion of women in Europe who use the Internet?

• 0.321 < p < 0.379

• 0.316 < p < 0.384

• 0.309 < p < 0.391

• 0.305 < p < 0.395

A survey of 800 women shoppers found that 17% of them shop on impulse. What is the 98% confidence interval for the true proportion of women shoppers who shop on impulse?

• 0.148 < p < 0.192

• 0.136 < p < 0.204

• 0.144 < p < 0.196

• 0.139 < p < 0.201

Answer explanation

The correct confidence interval is 0.139 < p < 0.201 because it captures the true proportion of women shoppers who shop on impulse with 98% confidence.