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1-5 Skills Practice
Descriptive Modeling and Accuracy
1. TEST SCORES A teacher compares the ratio of the number of questions answered correctly to the
total number of questions on a test as a metric. For a student to earn and A or B on a test, the ratio
must be greater than or equal to 0.8. The last test given by the teacher had a total of 40 questions.
Using this metric, what is the least number of questions a student can answer correctly and earn an
A or B on the test?
number of questions answered correclty
Ratio to earn an A or B - -
number of questions

Respuesta :

calculista

Answer:

The least number of questions a student can answer correctly is 32

Step-by-step explanation:

Let

x -----> the number of questions answered correctly

y ----> the  total number of questions on a test

[tex]ratio=\frac{x}{y}[/tex]

we know that

For a student to earn and A or B on a test, the ratio  must be greater than or equal to 0.8

so

[tex]\frac{x}{y} \geq 0.8[/tex]

For y=40 questions

Find the value of x

substitute

[tex]\frac{x}{40} \geq 0.8[/tex]

solve for x

Multiply both sides by 40

[tex]x \geq 0.8(40)[/tex]

[tex]x \geq 32[/tex]

so

The least number of questions a student can answer correctly is 32

Verify the ratio

For x=32, y=40

[tex]\frac{32}{40}=0.8[/tex]

Compare

[tex]0.8 \geq 0.8[/tex] ----> is ok

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