SAT question ec7b0eb8 (Probability And Conditional Probability)

Question

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. If one of the 799 teens surveyed is selected at random, what is the probability that the teen talks on a cell phone daily?

College Board · Accepted Answer

The correct answer is B. Choice B is correct. If one of the teens surveyed is selected at random, the probability that the teen talks on a cell phone daily is equal to the quotient of the total number of teens who reported that they talk on a cell phone daily, 415 , and the total number of teens surveyed, 799 . Therefore, this probability is equal to (415)/(799) .

CookSAT · Answer

Note: The expression 415/799 directly computes the probability from the table's column total and grand total.

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	$415$	$384$	$799$

Explanation

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Why the other choices are wrong

SAT Question ec7b0eb8: Probability And Conditional Probability answer and explanation with Desmos solution

Explanation

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Why the other choices are wrong