Q. INSTRUCTIONS: Read each problem carefully. Write solutions neatly. NO SOLUTION, NO POINTS. Express answers in lowest terms.1. Find the expected value and the standard deviation of each random variable.a,\begin{tabular}{|c|c|c|c|}\hlinex & 10 & 20 & 30 \\\hlineP(x) & 0.10 & 0.70 & 0.20 \\\hlinex∗P(x) & & & \\\hline\end{tabular}b.\begin{tabular}{|c|c|c|c|c|}\hlinex & 2 & 4 & 6 & 8 \\\hlineP(x) & 0.30 & 0.20 & 0.10 & 0.40 \\\hlinex∗P(x) & & & & \\\hline\end{tabular}
Calculate Expected Value Set A: Calculate the expected value for set a. Multiply each value of x by its corresponding probability P(x) and sum the results.Calculation: (10×0.10)+(20×0.70)+(30×0.20)=1+14+6=21.
Calculate Variance Set A: Calculate the variance for set a. Subtract the expected value from each x, square the result, multiply by the corresponding P(x), and sum all.Calculation: ((10−21)2×0.10)+((20−21)2×0.70)+((30−21)2×0.20)=121×0.10+1×0.70+81×0.20=12.1+0.7+16.2=29.
Calculate Standard Deviation Set A: Calculate the standard deviation for set a by taking the square root of the variance.Calculation: 29≈5.39.
Calculate Expected Value Set B: Calculate the expected value for set b. Multiply each value of x by its corresponding probability P(x) and sum the results.Calculation: (2×0.30)+(4×0.20)+(6×0.10)+(8×0.40)=0.6+0.8+0.6+3.2=5.2.
Calculate Variance Set B: Calculate the variance for set b. Subtract the expected value from each x, square the result, multiply by the corresponding P(x), and sum all.Calculation: ((2−5.2)2×0.30)+((4−5.2)2×0.20)+((6−5.2)2×0.10)+((8−5.2)2×0.40)=10.24×0.30+1.44×0.20+0.64×0.10+7.84×0.40=3.072+0.288+0.064+3.136=6.56.
Calculate Standard Deviation Set B: Calculate the standard deviation for set b by taking the square root of the variance.Calculation: 6.56≈2.56.