Final answer:
All the given options for Mike's earnings per hour are equivalent to $9 per hour, so there is no non-equivalent ratio among the provided choices (a, b, c, d).
Step-by-step explanation:
To determine the non-equivalent ratio for Mike’s earnings per hour, we need to find the ratio that does not equal the others when reduced.
We calculate Mike’s earning rate by dividing the total amount earned by the number of hours worked:
- $36 for 4 hours = $9 per hour
- $27 for 3 hours = $9 per hour
- $45 for 5 hours = $9 per hour
- $18 for 2 hours = $9 per hour
All the given options represent the same rate of $9 per hour. Therefore, there is no non-equivalent ratio listed among the options available (a, b, c, d).