Subtract 4 from both sides of the equation. It looks familiar now right? (y=mx+b is a linear equation)
Answer:
The percentage is 
Step-by-step explanation:
From the question we are told that
The population mean is 
The standard deviation is 
The percent of people who write this exam obtain scores between 350 and 650

Generally




From the z-table 
and 
=> 
=> 
Therefore the percentage is 
<span>To begin, each of the friends have made 4 bags of dough. This gives 12 bags at the outset. After 10 days, all 12 bags are made into (4*12) bags, or 48 bags. After 20 days, the 48 bags are made into (48*4), or the required 192 bags. After 20 days, then, the friends have the needed 192 bags.</span>