Test review: types of questions- some calculation needed

To determine the freshness of doughnuts coming out of the oven, a baker selects a doughnut every 30 minutes and checks it.

Systematic Sampling

To determine if a candidate for state senator is popular with voters, 25% of voters in 160 counties are surveyed.

Stratified Sample

To determine whether students think a new school library is needed, a computer generates a list of 100 random students and they are surveyed.

Simple Sample

To determine the theme of the school dance, the student council president surveys his homeroom class.

Convenience Sample

A physical education teacher posts an online survey about whether students would be interested in a 5K race. The responses received determine whether there will be a 5K race.

Voluntary Response Sample

A teacher at a middle school sends out a survey on a social network asking students to vote for their favorite field day activities. The teacher determines that the field day activities should include a water balloon toss, 3-legged race, and face painting. Is this valid? Which type of sample was used?

No, this is not valid because they used a biased sampling known as a voluntary sample, where respondents are chosen based on their accessibility and willingness to participate.

Each student at Longview Middle School is assigned a unique number. Twenty-five numbers are selected at random using a random number generator. The corresponding students are then surveyed about their interest in adding new after school activities. The teacher conducting the survey determines that students would be interested in a drama club and a tutoring program. Is this a valid inference? Which type of sample was used?

Yes it is valid. They used unbiased simple sample.

The guest services staff at an amusement park surveys 50 randomly selected season pass holders and 50 randomly selected non-season pass holders to gauge interest in a new attraction. The staff concludes that park visitors would be very interested in a new water ride next season. Is this a valid inference? Which type of sample was used?

Yes, this is valid. They used a stratified random sample, which ensures representation from both season pass holders and non-season pass holders.

In a random sample of 200 sets of earbuds, 3 sets were found to have defects. Suppose there are 5,000 sets in a production run. Let n represent the number of sets with defects that can be expected in the entire production run.

The expected number of defective sets can be calculated using proportions; in this case, n is expected to be 75 sets with defects in the entire production run.

The principal of a middle school surveys a random sample of 50 students and finds that 22 of them participate in extracurricular clubs or sports. Suppose there are 275 students in the middle school. Let n represent the number of students in the school who participate in extracurricular clubs or sports.

The expected number of students who participate can be calculated using proportions; in this case, n is expected to be approximately 121 students participating in extracurricular clubs or sports.

We are raising funds to purchase 75 instruments. We survey 25 random students planning to join band. Based on the results of the survey, predict how many trumpets the music teacher should order.

21

A hose manufacturer tests the fittings on every 20th hose on an assembly line. Out of 145 hoses tested, 2 had issues with loose fittings. How many hoses with loose fittings should the manufacturer expect out of 2,900 hoses?

40

Meredith conducts a random survey of 45 students at her school and asks whether they are right-handed or left-handed. The results are shown in the table.

 

left-handed	5
right-handed	40

 

Based on the survey results, predict how many of the 468 students in Meredith's school are left-handed.

52 students are expected to be left-handed.

The owner of Freedom Surf Shop conducted a survey among a random sample of his customers asking them what new product they would like to see the store carry. The survey showed that 35% of the store's customers would like to see skimboards stocked at the store. If the store has 960 customers next month, predict how many of them might be interested in buying a skimboard.

336 customers are expected to be interested.

\What is the mean rounded to nearest tenth?

2.5

If the mean is 2.5. What is the MAD?

0.54

The majority of the data are clustered between 14 and __ pounds.

14 and 19 pounds

Does this dot plot show high variability or low variability?

High Variability

Does this dot plot show high variability or low variability?

LOW

Below are two dot plots containing sample means from the same population.

 How many samples are represented in each plot?

30

True or False: The median for the Hickory Bulldogs wins is less than the median number of wins for the Claryville Catamounts.

True

Which of the following inferences IS true about the data?

a. Pop albums and country albums have the same number of songs with little variation.

b. A randomly selected country album is likely to have more songs than a randomly selected pop album.

B

The following are the ages of 13 music teachers in a school district.

Notice that the ages are ordered from least to greatest.

Give the interquartile range for the data set.

27

The following are the ages of 13 music teachers in a school district.

Notice that the ages are ordered from least to greatest.

Give the median for the data set.

44

What is the median of this data?

66

Which city has a larger median noon temperature?

B

Which city has a smaller range of noon temperatures?

A

Find the median and the interquartile range (IQR) of both data sets.

Athlete A median: 31 IQR: 7

Athlete B median: 21 IQR: 14