Mallory works 20 hours a week as a website designer and earns $42.50 per hour. If Mallory saves 1
2
of her total website-design earnings each week, how much will she save in 4 weeks?

If Mallory makes $42.50 per hour and she works 20 hours a week, we multiple those two and we get:

42.5 * 20 = 850

So she earns $850 per week.

Mallory saves half of that amount she would have $425 per week.

In 4 weeks she would have:

425 * 4 = 1700

Mallory will save $1,700 in four weeks.

The scale factor of what ?