Number two is thirty weeks
9=9m
Next, what you want to do is divide both sides by m to get the variable.
m=1
M (Mean) = 20,500;
SD (Standard Deviation) = 55
1 ) 20,555 = 20,500 + 55 = M + 1 SD
Answer: 50% + 34.1% = 84.1%
2 ) 20.610 = 20,000 + 110 = M + 2 SD
Answer: 10% - ( 50% + 34.1% + 13.6% ) = 100% - 97.7% = 2.3%
3 ) 20,445 = 20,500 - 55 = M - 1 SD
Answer: 50% - 34.1% = 15.9%
Let the distance be x miles
Time = Distance / speed
Time taken by Mike to go to his friend's house = x / 40 hours
Time taken by him to return = x / 45 hours
Total time = x / 40 + x / 45 = 4 hours
= 9x + 8x = 1440 miles
17x = 1440
= x = 1440 ÷ 7
= x = 84.706
Time taken to return home = 84.706 /45= 1.882 hours .
Therefore , Mike took 1.882 hours to reach home .
