David has earned the following test grades: 89, 96, 99, 85. What is the
grade David has to earn on his 5th test to maintain a test
average of 90?

81

Step-by-step explanation:

Required average= 90

let the required grade be x

Average= Sum of n numbers

90= 89+96+99+85+x divide by 5

450= 369+x

x = 450-369

x=81

how many players are there?

step-by-step explanation:

the mistake in the pattern is that :

b. the decimal point was moved one too many place values each time

the correct pattern could be made by :

b. moving the decimal point to the right the same numbers of place values as the exponents