so the test he scored lowest is 69 so discard this score and put x for it
average=numbers added together then summ is divided by number of numbers exg
average of 2 and 4 and 5 is 2+4+5=11 then 3 numbers so 11/3 is average or aprox 3 and 2/3 so
\(\frac{76+84+x+74+91}{5}\)=average
he wants his new average to be at least 82 so
\(\frac{76+84+x+74+91}{5} \geq 82\)
solve
\(\frac{76+84+x+74+91}{5} \geq 82\)
treat as equation
first add like terms in top
\(\frac{325+x}{5} \geq 82\)
multiply both sides by 5 to clear fraction
325+x \(\geq\) 410
subtract 325 from both sides
x \(\geq\) 85
he must get \(\geq\) 85 to get an average of at least 82
