70. Suppose matrix A [12 3; 4 5 6]. What is mean(A(:))? a. 2.5 3.5 4.5] b. 2; 5] c. 3.5 d. Error 71. Which one of the following is not part of data analysis a. Preprocessing b. Modeling c. Visualizing d. Data authorization 72. In Matlab, which one is used to represent missing or outlier data points? a. None b. NaN C. none d. null 73. When applying moving average in Matlab, function filter can be used. Suppose we choose window size of 8, what value should be used for the first argument? b. 2/8 d. 8 74. We discussed in the class that average can be represented by mean, median, or mode. When mean is used to represent average, what else should we provide for a better picture? a. Confidence interval b. Alpha error probability c. Beta error probability d. Standard deviation 75. In Matlab, which one of the following functions is used to draw a line? a. plot b. scatter c. polyfit d. polyval