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Not using excel The solution is by laws

Q4. Solve the following questions. (a) A garden contains 39 plants. The following plants were chosen at random, and their heights were recorded in cm: 38, 51, 46, 79, and 57. Calculate their heights' standard deviation. (1)) Calculate mean, variance, and standard deviation of the following data: 57, 64, 43, 67, 49, 59, 44, 47, 61, 59 [c] Calculate mean, variance, and standard deviation of the following data