Graphing and finding logarithmic function for given data

In an art class, students were tested at the end of the course on a final exam. Then they were retested with an equivalent test at subsequent time intervals. their scores after time x in months, are give in the following table
Time, X (in months) Score, y
1 84.9%
2 84.6
3 84.4
A) Use a graphing calculator to fit a logarithmic function y=a + b In x to the data.
B) Use the function to predict test scores after 8, 10 24 and 36 months.
C) After how long will the test scores fall below 82%?
If i can get an explantion on how to input this and get the a + b numbers to put in the calculator. I know that y is the percentage and x is the months but how to figure out the a + b portion is confusing me.

Solution Preview

HI,

Please find the explanations/solutions attached herewith.

I am also attaching the excel file.

In an art class, students were tested at the end of the course on a final exam. Then they were retested with an equivalent test at subsequent time intervals. their scores after time x in months, are give in the following table
Time, X (in months) Score, y ...

Solution Summary

The following posting helps with problems involving a graphing calculator and functions to predict test scores. A step by step detailed solution is provided.

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