The least-square regression line has a slope of:
m=(nΣxy-ΣyΣx)/(nΣx²-ΣxΣx)
and a y-intercept of:
b=(Σy-mΣx)/n
In this case: n=7, Σxy=4899, Σy=391, Σx=85, Σx²=1153 so
m=(7(4899)-391*85)/(7(1153)-85*85))=1058/846
b=(391*846-85*1058)/(7*846)=34408/846
So the line of best fit is:
y=(1058x+34408)/846 and if we approximated this as your answers see to have done....
y=1.25x+40.67
Answer:
88 problems
Step-by-step explanation:
Set this problem up as fractions
86/x = 98/100
Cross multiply
86 × 100 = x × 98
8600 = 98x
Divide both sides by 98
87.75... = x
Round to nearest whole number
87.75 rounds up to 88
88 problems
maybe bc of how many times you can add the number itself
The answer to you question is c
