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6 7 The position of a moving object has been recorded as shown in Table P7. (a) Find the acceleration of the object at t = 1.8 sec. using the four-point backward difference formula. (b) Using the result of (a), and the three-point central difference formula, predict the position at t = 2.1 sec. Table P7 Time, t Position, X "sec ) (meters) 0.6 0.68 0.9 0.83 1.2 0.91 1.5 1.19 1.8 1.43