Ascuba diver dove from the surface of the ocean to an elevation of -69 9/10 feet at a rate of -21.5 feet per minute. after spending 10.75 minutes at that elevation the diver adsense to an elevation of -8.9 feet. the total time for the dive so far was 17.125 minutes. what was the rate of change in the divers elevation during the ascend? round your answer to the nearest hundredth