For the problem I thought it was asking about the lowest and greatest values. But that is incorrect therefore, my answer is wrong. How do I go about this problem then? How would I solve this?

You're right, this problem is asking for the least and greatest values. But, we have to take a bit of a closer look at the stem and leaf plot.

The left side is the ones place and the right side is the tenths place.

Using that information, the least data value is 2.5, and the greatest data value is 5.7.

Hope this helps!

cross multiplying, we get :

⇒ (3) × (5) = (9) × (x)

⇒ 15 = 9x