You are right in thinking that the base of the logarithm doesn't matter. It only affects the spread of the data points if you were to plot them, but would not ultimately have any effect on the slope of the line (but it would on the y-intercept).
One major discrepancy I'm noticing is in the values you found for
. For example, if
, then you should have
. Not sure how you got -7.0, and the same goes for the rest of your table of values.
Another thing is that the provided solution suggests you take the average the first and last pairs of consecutive data points, and use these values in the slope formula to obtain the best-fit line's slope. If that's the case, then you should have

(i.e. you have to take the average of the given values, then use those averages in the
expressions - but this doesn't significantly affect the slope you found)
Ultimately, I think the problem is that your expression for the slope appears to be
, when the solution says it should be the reciprocal. I'm of the opinion that your slope is correct, since the experiment refers to
(and hence
) as the independent variable, and so
would serve as the "run" and
would serve as the "rise".
Answer:
The required equation is 
Step-by-step explanation:
Consider the provided information.
Let P represent the number of pages left to read after t hours.
Shryia read a 480-page-long book cover to cover in a single session, at a constant rate. After reading for 1.5 hours, she had 402 pages left to read.
Total number of page Shryia read in 1.5 hours is:
480-402 = 78
It is given that the rate is constant i.e 1.5 hours,
Therefore, she read 78 pages in 1.5 hours.
She can read
page per hour
The required equation is:

Where t represents the number of hours.
Add 26 and 73 = 99 then divide 99 by 6 = 16.5 which is 17 vases
Your equation is 6/25 = d/30. to solve this equation we have to get d by itself! to do this, you have to multiply each side by 30 since d is being divided by thirty. d/30 x 30 = d, 6/25 x 30 = 7.2, or 7 2/10
therefore, d = 7.2
hope this helps!