This would be considered a reasonable estimate because if you were to use estimation, you can round 289 to the nearest hundred (300), which is divisible by 60. When dividing 300 / 60, you will get 5 hours, which is 0.5 greater than 4.5 therefore making it a reasonable estimate. In addition, when actually dividing 289 / 60, you will get approximately 4.8 hours, which is close to the estimate, 4.5 hours.
