SR Week 8 Activity

For this problem, you have the population proportion of 0.28 and standard deviation of 0.02. What value is 2 standard deviations below the population proportion?

Answer explanation

2 standard deviation below the value would mean you want to multiply the STDEV by 2 and subtract it from the population proportion:

2*0.2 = 0.4; you want the value that is 0.4 below 0.28:

0.28 - 0.4 = 0.24

_______ is a part of a group being surveyed.

• Sample
• Population
• Random Sample
• Quartile

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

• Sample

• Random Sample

• Population  

• Quartile

_________ is a sample in which each individual or object in the entire population has an equal chance of being selected.

• Sample
• Population
• Random Sample
• Quartile

True or False: all samples lead to a good prediction about an entire population.

• True
• False

A toy store owner wants to track how much kids spend each month on toys. He decides to sample the next 50 kids that make purchases at the store. Twenty kids spend over $25 on their purchases. Which choice best represents the population?

• All the kids who buy toys

• 50 kids that make purchases

• All kids

• Twenty kids that spend over $25

A mayor wanted to see if the people in their town thought they were doing a good job. They survey 1,000 adults living in their town to find that 65% think they are doing a good job. Which choice best represents the sample?

• 1,000

  adults living in their town that are

  over 65.

• 65%

  of people that think they are doing a good job

• All adults

  of the town.

• 1,000

  adults living in their town

Select all the reasons why random samples are preferred over other methods of getting a sample.

• A random sample is always the easiest way to select a sample from a population.

• A random sample is likely to give you a sample that is representative of the population.

• A random sample is a fair way to select a sample, because each person in the population has an equal chance of being selected.

A mayor wanted to see if the people in their town thought they were doing a good job. They survey 1,000 adults living in their town to find that 65% think they are doing a good job. The 65% of people that think they are doing a good job is an example of a statistic.

• True

• False