Answer:
The correct punctuation for this sentence is "Dan is a great coach; he motivates the girls in a positive way "
Step-by-step explanation:
The most common use of a semicolon is to join to independent sentences, Dan is a great coach is a complete an independent sentence, He motivates the girls in a positive way is also a complete and independent sentence, the semicolon is used instead of a conjunction like and to connect the two ideas into one sentence.