Samples and Percentages

A recent survey found that out of 400 random American adults, 89% pay their bills on time. The margin of error in this survey was 2%. What is the interval of values in which the truth is likely found?

• 89% - 91%

• 87% - 89%

• 87% - 91%

• 388 - 402

A recent survey found that 77% of high schoolers use their phones more than 4 hours a day on average. The margin of error was 3%. What is the interval for which we could expect to find the truth of the population?

• 77% - 80%

• 74% - 77%

• 74% - 80%

• 50 million high schoolers - 120 million

• If the proportion of old people wearing dentures is greater than 60%.

• If the proportion of old people wearing dentures is 61%.

• If the proportion of old people wearing dentures is more than 65%.

• If the proportion of old people wearing dentures is 65%.

A random sample of shoppers chose between two similar products, and the percent who chose Brand A was recorded. The table shows the results of 20 simulations. Based on the simulations, which of the following is the most likely margin of error for the sample?

• ±1

• ±2.5

• ±8

• ±16

The results of a survey suggested that 54% of the voters will vote for a particular candidate in an election. The results from 100 computer simulations of this situation are shown below. Based on the margin of error and these simulations, what is the range of the percentages of votes this candidate could receive?

• 0.45 to 0.63

• 0.48 to 0.58

• 0.54 to 0.74

• 0.59 to 0.69

A class does a simulation of flipping a coin 20 times, and records the proportion of "Tails" obtained. By running the simulation 100 times, they create a distribution as shown. Use the sampling distribution to estimate the mean of the distribution. 

• 0.51

• 0.45

• 0.62

• 0.24

In order to estimate the average age of a penny in circulation, Rebecca uses an advanced statistical technique to simulate the process of selecting 100 pennies and recording the ages. The graph shows the result of her simulations. Based on her work, which of the following is the best estimate for the margin of error that Rebecca should use when she comes up with her estimate for the mean age of a penny in circulation?

• 3

• 6

• 12.5

• 14.5

The annual profit increases for ten companies are given below. The increases are expressed as percentages:
5 8 8 7 9

3 5 4 6 4

The interquartile range (IQR) of these annual profit increases is

• 3

• 4

• 6

• 9

The annual profit increases for ten companies are given below. The increases are expressed as percentages:
5 8 8 7 9

3 5 4 6 4

This data can best be displayed using a

• histogram

• box plot

• scatterplot

• parallel stem plot

The heights of a very large sample of women aged 80 years or more were recorded and were found to follow a normal distribution. The mean of the distribution was 164cm and the standard deviation was 4.5cm.

The percentage of these women with a height between 159.5cm and 173cm is closest to

• 47.5%

• 68%

• 81.5%

• 95%