Texting behavior Talks on cell phone daily Does not talk on cell phone daily Total
Light 110 146 256
Medium 139 164 303
Heavy 166 74 240
Total 415 384 799
##### In a study of cell phone use, 799 randomly selected US teens were asked how often they talked on a cell phone and about their texting behavior. The data are summarized in the table above. Based on the data from the study, an estimate of the percentage of US teens who are heavy texters is 30% and the associated margin of error is 3%. Which of the following is a correct statement based on the given margin of error?
Difficulty: Hard
A:

Approximately 3% of the teens in the study who are classified as heavy texters are not really heavy texters.

B:

It is not possible that the percent of all US teens who are heavy texters is less than 27%.

C:

The percent of all US teens who are heavy texters is 33%.

D:

It is doubtful that the percent of all US teens who are heavy texters is 35%.

Difficulty: Hard
A:
Value Frequency
70 4
80 5
90 6
100 7
B:
Value Frequency
70 6
80 6
90 6
100 6
C:
Value Frequency
70 7
80 6
90 6
100 7
D:
Value Frequency
70 8
80 5
90 5
100 8
##### Each face of a fair 14-sided die is labeled with a number from 1 through 14, with a different number appearing on each face. If the die is rolled one time, what is the probability of rolling a 2?
Difficulty: Easy
A:

$\frac{1}{14}$

B:

$\frac{2}{14}$

C:

$\frac{12}{14}$

D:

$\frac{13}{14}$

Difficulty: Easy
A:

11

B:

20

C:

44

D:

55

##### Jennifer bought a box of Crunchy Grain cereal. The nutrition facts on the box state that a serving size of the cereal is $\frac{3}{4}$ cup and provides 210 calories, 50 of which are calories from fat. In addition, each serving of the cereal provides 180 milligrams of potassium, which is 5% of the daily allowance for adults. If $p$ percent of an adult’s daily allowance of potassium is provided by $x$ servings of Crunchy Grain cereal per day, which of the following expresses $p$ in terms of $x$?
Difficulty: Hard
A:

$p=0.5x$

B:

$p =5x$

C:

$p=(0.05)^{x}$

D:

$p=(1.05)^{5}$

Prices of 14 Different Cars
Type of car Priced at no more than $25,000 Priced greater than$25,000 Total
Nonhybrid 5 3 8
Hybrid 2 4 6
Total 7 7 14