Josh was training for the 400 m race. Josh had a personal record of 65.2 three seconds in a practice event he had a time of 65.5 six seconds which volume is a reasonable estimate of the difference between Josh record time and his practice time.
The difference between Josh's personal record time and his practice time can be estimated by finding the absolute difference between the two times.
65.5 (practice time) - 65.2 (personal record time) = 0.3 seconds
A reasonable estimate of the difference between Josh's record time and his practice time is approximately 0.3 seconds.