Final answer:
A reasonable resistance training intensity to use while developing motor skills for beginners is 40-50% 1 RM.
Step-by-step explanation:
When prescribing 1 RM (repetition maximum) for beginners, a reasonable resistance training intensity to use while developing motor skills would be 40-50% 1 RM. This intensity allows beginners to focus on proper form, technique, and coordination without placing excessive stress on their muscles and joints. Starting at a lower intensity also provides a foundation for gradual progression as the individual becomes more comfortable and proficient in the exercises.