d) collect gas produced with a gas syringe
-compare volumes at different temperatures
-incubate mixture and different temperatures
That means the medicine is working and to continue to take the medication
Explanation : x = 79 marks
The marks scored by Mike on four math test are 88,91,75 and 72.
Average of marks, A = 81
Let in fifth test he scores x marks.
The formula for finding average is :




In the fifth test he scores 79 marks.
Hence, this is the required solution.
When an active cold front over takes a warm front is creates tornadoes.