Question

Which logarithmic graph can be used to approximate the value of y in the equation 3y = 7?

Answer 1

We have that
3^y = 7
applying log both members
log(3^y)=log 7
y*log 3=log 7
y=log 7/log 3

using the logarithmic graph of y=log x

I graphically determine the values ​​for x = 3 and x = 7

see the attached figure

for x=3
log 3=0.48

for x=7
log 7=0.85

therefore
y=log 7/log 3-----> y=0.85/0.48-----> y=1.77

the answer is
the approximate value of y is 1.77