what is the pattern ant next 3 numbers in this sequence? 1, 2, 4, 7, 10, 15...?

[The once great OZ]

I found an answer in wiki answer saying the next numbers are 22.5, 33.75 and 50.625 but this is supposed to be 5th grade math so i doubt it. I think there's a typo, but there are multiple copies of this example an several grades so maybe i am just blind?

Thanks