nothing
90.
(77+83+89+86+x)/5=85 (335+x)/5=85 (335+x)=85*5 335+x=425 x=425-335 x=90 He must get 90% on his fifth test to average 85%.
The average is all the numbers added together and then divided by the # of numbers.(80+85+90+88+86+83+89+70)/8=671/8=83.875Order of operations has the brackets first and then the division.
The average range for the Wechsler Intelligence Scale is typically considered to be between 90 and 110, which falls within the normal range of intelligence. A score below 90 may indicate below-average intelligence, while a score above 110 may indicate above-average intelligence.
85
85+85=170+90=260+100=360/4=90 Problem solved.
I would say from about 78-90 on an average
For 77 83 69 72 85 90 95 75 55 45: σ=15.4071
The average "IQ" on many standardized IQ tests is a standard score of 100. The "Average Range" is often 90 to 110 or 85 to 115, depending on the measure used.
100+90+110=300 300 divided by 3 =100
90