The scatterplot shows the relationship between two variables, x and y. An equation for the....

Bluebook Digital SAT Practice Test 6, Section 2, Module 1, Question 16:

The scatterplot shows the relationship between two variables, x and y. An equation for the exponential model shown can be written as y = a(b)^x, where an and b are positive constants. Which of the following is closest to the value of b?

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[OverclockingCowboy]

There is a QUICK answer to this problem by observing that the graph is a decaying exponential. The “b” value has to be less than 1. And the only option is Choice A.

Note also that “b” is a multiplier. We can take the 2 most accurate adjacent numbers and that would give you the value of b. For instance, 4 gives you 60, 5 gives you 50.

50/60 = 0.833

Just remember that most (not all) SAT questions are solvable without a calculator. Do not abuse Desmos! You can solve this problem in Desmos by simply doing a regression with 2 or more points from the graph.

[isaacchang]

How to 10th root in desmos calculator?