If the dolphins are fed half a bucket of fish then half of that would be a quarter, therefore the sea otters are fed 1/4 of a bucket.
4.5, since 6 times .75 (the model height) is 4.5
If you would like to simplify 21/78, you can do this using the following step:
21/78 = 7/26
<span><span>The result is </span>7/26 <span>(this is not a mixed number, because mixed
numbers can be made from numbers greater than 1 and 7/26 is less than 1).</span></span>