SOLUTION: in regression line y=a+bx,y denominates the telephone bill amount and x denominates the units consumed.when 200 unit were consumed the Bill amount was Tsh 2500000 And when 500 uni

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Question 1174630: in regression line y=a+bx,y denominates the telephone bill amount and x denominates the units consumed.when 200 unit were consumed the Bill amount was Tsh 2500000 And when 500 unit were consumed the bill amount was tsh 4900000 find a and b
Answer by MathLover1(20855) About Me  (Show Source):
You can put this solution on YOUR website!

y=a%2Bbx
y+denominates the telephone bill amount
and
x denominates the units consumed
given:
when x=200 unit were consumed the Bill amount was Tsh y=2500000
so we have
2500000=a%2B200b.............eq.1
and when 500 unit were consumed the bill amount was tsh y=4900000
so we have
4900000=a%2B500b.............eq.2

to find a and b solve system

2500000=a%2B200b.............eq.1
4900000=a%2B500b.............eq.2
--------------------------------------------------subtract eq.1 from eq.2
4900000-2500000=a-a%2B500b-200b
2400000=+300b
b=2400000%2F300
b=8000

go to
2500000=a%2B200b.............eq.1, substitute b
2500000=a%2B200%2A8000
2500000=a%2B1600000
2500000-1600000=a
a=900000

and, your equation is:
y=900000%2B8000x