Answer:
x = 95
Explanation:
Given that,
Jax scores on the last 5 tests are 78,92,86,94,95.
We need to find the score he need to have an average of 90.
The formula for average of few number is given by :
Average = sum of observations/total no of observation
Let he score x in test 6. So,

So, he must score 95 in the next test so that its average is 90.