Your answers are correct . . . Nice work!
. . I used a "back door" approach to these problems.
1. An investment of $1500 paid interest of $45 during a certain period.
How much interest would an investment of $2000 pay,
invested at the same rate for the same length of time?
We are investing: .2000/1500 = 4/3 as much money.
The interest will be 4/3 as much: .4/3 × $45 .= .$60
2. In baseball a player's batting average
is the ratio of hits to the number of times he or she has batted.
Thus, if the player has an average of .300,
it means he or she got 300 hits out of 1000 at bats.
In order to have an average of .300,
how many hits would the batter have to get in 400 times at bat?
A batting average of .300 means he got hits 30% of the time.
For 400 at-bats, he needs: .30% of 400 .= .120 hits