30-f+8f=30
30+7f=30
Move +30 to the right side. Sign changes from +30 to -30.
30-30+7f=30-30
7f=0
Divde by 7
7f/7=0/7
Cross out 7 and 7, divide by 7. Becomes 1*1*f=f
f=0
Answer: f=0
Answer:
$63
Step-by-step explanation:
30% of 90 is 27
90-27=63
In order to estimate the mean, you need to choose a value to represent the number in each category of accidents. It is often convenient to use the middle value of the range.
.. (4*6 +10*10 +15*6 +20*9)/(6 +10 +6 +9) = 394/31 ≈ 12.7
