What is the difference between ratio and interval schedules of reinforcement

Interval schedules involve reinforcing a behavior after an interval of time has passed.Difference between variable interval & variable ratio.When the number of responses or the amount of time between reinforcement varies, and becomes unpredictable, it is known as the variable interval reinforcement.These schedules are described as either fixed or variable, and as either interval or ratio.What is the difference between fixed ratio and variable ratio reinforcement schedules?

A) reinforcement is given at such a high rate that it stops working b) reinforcement is thinned too quickly and the behavior diminishes or disappears c) reinforcement is thinned too quickly and the behavior increases significantly d) reinforcement is delayed too long resulting in the display of inappropriate behavior(a) higher rates occur on ratio schedules, and (b) ratio schedules are unable to maintain responding at low rates of reinforcement (ratio strain).The zero point actually does not represent a true zero, but considered to be zero.The reinforcement schedule will average out to be rewarded for every five responses, but the actual delivery schedule will remain unpredictable.The other two are interval schedules or schedules based on how much time has elapsed.

Variable ratio schedules maintain high and steady rates of the desired behavior, and the behavior is very resistant to extinction.