Question 86 of 208MediumMCQ
The mean and variance of the data 4, 5, 6, 6, 7, 8, x, y, where x < y, are 6 and 49 respectively. Then x4+y2 is equal to Solutions · 1
Official solution
Mean =6: 84+5+6+6+7+8+x+y=6⟹x+y=12 ...(i)
Variance =49: 84+1+0+0+1+4+(x−6)2+(y−6)2=49⟹(x−6)2+(y−6)2=8 ...(ii)
From (i) and (ii): x=4,y=8 (since x<y).
x4+y2=44+82=256+64=320 Answer the question to unlock