[1U ESTIU N 4 The following data is the number of lorries that crossed a toll plaza in a period of 3D days the first of its opening. 31 26 35 31 3 '3' 3i] 29 33 32 2'? 33 35 25 2E 25 24 35 3D 39 2 1 3U 25 2E 29 29 29 34 3B 3? :13 a} Based on the Sturges rule. construct a frequencv distribution for the above data bv using the lowest value as the lower boundarv of the first class. b] From the constructed frequencv distribution, calculate the mean, median and mode of the number oftrucks through the toll plaza. c} Calculate the standard deviation. d] What is the form of skewness for the data distribution? Explain vour