alter working 4 hours, frank has made 21 machine parts.at the same rate how many parts can he make in 7 hours? 4(21)/7,7(21),7(21)/4,7(4)/21,7(4)(21)?

Please post your answer and we'll be glad to check it.

Look at dimensional analysis.

21 parts/4 hrs x ?hrs = ?parts.

i choose a)4(21)/7

How can a) be the right answer? 4(21)/7 = 12. The problem has stated that he made 21 parts in 4 hours. How can he make fewer parts in more hours?

Please try again.

Hint: you could set up a proportion:
4 is to 21 as 7 is to x

d)7(4)/21

7(4)/21.

Do the math. Does the answer make sense?

To find out how many machine parts Frank can make in 7 hours, we can use the concept of proportions.

Given that Frank can make 21 machine parts in 4 hours, we can set up the proportion:

4 hours / 21 parts = 7 hours / x parts

To solve for x, the number of parts Frank can make in 7 hours, we can cross-multiply:

4 hours * x parts = 21 parts * 7 hours

Now, let's solve for x:

4x = 21 * 7

Multiply 21 by 7:

4x = 147

Divide both sides of the equation by 4:

x = 147 / 4

Simplifying the calculation:

x ≈ 36.75

Therefore, Frank can make approximately 36.75 machine parts in 7 hours.