Keystone Test Algebra: Functions and Data 2

Question 1

A function is defined as f(x) = 3x² - 2x + 1. What is f(-2)?

Accepted Answer

17

Answer

f(-2) = 3(-2)² - 2(-2) + 1 = 3(4) + 4 + 1 = 12 + 4 + 1 = 17.

Question 2

Which scatter plot description indicates a strong negative correlation?

Accepted Answer

Points cluster tightly along a line going down to the right

Answer

A strong negative correlation means as x increases, y decreases, shown by points tightly clustered along a downward-sloping line.

Question 3

The table shows: x = {1, 2, 3, 4} and y = {5, 8, 11, 14}. Which function models this data?

Accepted Answer

y = 3x + 2

Answer

The common difference is 3 (slope), and when x=1, y=5: 3(1)+2=5, confirming y = 3x + 2.

Question 4

If g(x) = 2x - 5, for what value of x does g(x) = 0?

Accepted Answer

x = 2.5

Answer

Set 2x - 5 = 0, so 2x = 5, giving x = 2.5.

Question 5

A data set has values: 4, 7, 7, 9, 13. What is the mean of this data set?

Accepted Answer

8

Answer

Mean = (4 + 7 + 7 + 9 + 13) ÷ 5 = 40 ÷ 5 = 8.

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