Question

Updates Transaction Frequency Selects: X Inserts Deletes Non-Unique Selects Joins New order 44 23 11 12 0 C Payment 44 4.2 3 0.6 0 1 C Order status 11.4 4 0 0 0.6 C Delivery 120 4 130 C 10 0 C tock level 4. 0 0 0 0 1 a) Determine the mean and standard deviation of the number of selects operations for transaction from the distribution of types shown the above table. Round the answers to three decimal places. 17.608 Mean= 24.724 Standard deviation b) Determine the mean and standard deviation of the total number of operations (selects, updates,, and joins) for a transaction from the distribution of types shown in the table below. Round the answers to three decimal places. x 34.130 Mean 49.298 Standard deviation =

Answer 1

a) The observations are: {23, 4.2, 11.4, 130, 0}.

The mean = $\frac{1}{5} \sum_{i = 1}^{5} X_i$ = 33.72. (Ans).

The standard deviation = $\sqrt{\frac{1}{5-1} \sum_{i = 1}^{5}( X_i - \overline{X})^2}$ = 54.5239. (Ans).

b) The observations are: {46, 8.8, 12, 260, 1}.

The mean = 65.56. (Ans).

The standard deviation = 110.0544. (Ans).