Question

Of the 50 students in the cafeteria, 7 have red hair. Suppose there are 750 students in the school. Write a proportion that could be used to predict the number of students who have red hair. Use x to represent the number of students who have red hair.

Answer 1

Answer:

Given:

Of the 50 students in the cafeteria, 7 have red hair.

Total number of students = 750

To find:

The proportion that could be used to predict the number of students who have red hair.

Solution:

Let x represent the number of students who have red hair.

The ratio of student having red hair to the total number of students are

Ratio₁ = 7 / 50

Ratio₂ = x / 750

The number of students having red hair is proportional to the total number of students. So, the above ratios are equal.

x / 750 = 7 / 50

Multiply both sides by 750.  

x / 750 × 750 = 7 / 50 × 750

x = 7 × 15

x = 105

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Hope it helps you!!

:)

Answer 2

Answer:

Among 50 Students in the cafteria 7 have red hair.

Proportion of studemts having red hair is

$\frac{7}{50}$

so,

$\frac{x}{750 } = \frac{7}{50} \\ or \: 50x = 7 \times 750 \\ or \: x = \frac{7 \times 750}{50} \\ x = 105$

105 students may have red hair based on the proportion in the cafeteria.