Question 1029221
<pre>
The z-scores should be the same under both systems.

The z-score formula is

{{{z=(x-mu)/sigma)}}}

For the first test the z-score formula is

{{{z=(x-24)/4.5)}}}

Since he scored x=29 on the first test, his z-score
was

{{{z=(29-24)/4.5)}}}

{{{z=5/4.5)}}}

{{{z="1.1111..."}}}

For the second test the z-score formula is

{{{z=(x-70)/11.3)}}}

To find the equivalent x-score on the second test 
the z-score would be the same, so we substitute
1.1111... for z and solve for x:

{{{"1.1111..."=(x-70)/11.3)}}}

Multiply both sides by 11.3

{{{"12.5555..."=x-70}}}

{{{"82.5555..."=x}}}

Answer: 82.5555...

Edwin</pre>