The best estimate of the number of those parents likely to support the new proposal is 319. So the option is (B) 319.
What is constant of proportionality?
Firstly, there is proportional relationship.
Two values x and y are said to be in a proportional relationship if x=ky, where x and y are variables and k is a constant.
The constant k is called constant of proportionality.
Parents of students at a middle school were randomly selected to participate in a survey.
42 out of 60 parents who were surveyed support a proposal to buy new computers.
There are a total of 456 parents with students at the middle-school.
[tex]\dfrac{42}{60} = \dfrac{x}{456} \\\\\\x = \dfrac{42}{60} \times 456\\\\x = \dfrac{7}{10} \times 456\\\\x = 319[/tex]
Therefore, the best estimate of the number of those parents likely to support the new proposal is 319.
Learn more about directly inversely proportional relationship variable here:
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