Ellie compared 4/7 and 5/3 by first comparing each fraction to 1/2 and 1.

Step 1: 4/7 is less than 1 but more than 1/2

Step 2: 5/3 is more than 1

Step 3: so, 4/7 > 5/7

In which step did

Ellie make her first mistake?

Step 3

Step-by-step explanation:

She made her first mistake in Step 3.

This is because 4/7 is actually less than 5/3.

Step 1 and 2 are mathematically accurate.

1/2 is less than 1.

So, since 4/7 is only greater than 1/2 and not greater than 1 as compared to 5/3 which is actually greater than 1, she should have concluded that 4/7 is less than 5/3.

Therefore, Step 3 contains the mistake.