7) What must be the sum of the P(X) in the mean and variance of discrete random variable? A. 1% B. 10% C. 100% D. 1 000%Name: Grade / Strand: MEAN AND VARIANCE OF DISCRETE RANDOM VARIABLE Directions: Read and understand each question carefully. Choose the letter of the best answer then write it on the space provided. 1) What measure should you use to determine what most likely be the probability of an event to happen? A. Variance of discrete random variable C. Simple Variance B. Mean of discrete random variable D. Simple Mean 2) What measure should you use to determine how far or close the probability of events from the center or the mean? A. Variance of discrete random variable C. Simple Variance B. Mean of discrete random variable D. Simple Mean 3) What do you call the weighted average of the possible values that a random variable can take? A. Variance of discrete random variable C. Simple Variance B. Mean of discrete random variable D. Simple Mean 4) Which tells us how much we can expect results to deviate from expected value? A. Variance of discrete random variable C. Simple Variance B. Mean of discrete random variable D. Simple Mean 5) Which of the following statements is a description of low variance? A. The probability of scores is almost the same as the mean. B. The data are close to the mean. C. Both statements A and B D. None of the above 6) Which of the following statements is a description of high variance? A. The probability of scores is almost the same as the mean. B. The probability of scores is scattered around the mean. C. The data are closed to the mean. D. All the above.F. EVALUATION Direction: Find the mean, variance, and standard deviation of the following probability distribution then interpret the computed values. 1) Variable z representing the number of male teachers per Elementary school. X 2 14 5 6 P(x 40% 32% 11% 9% 8% 2) The number of mobile phones sold per day at a retail store varies as shown in the given probability distribution below. Find the expected number of mobile phones that will be sold in one day. 30 33 38 40 50 P(X) 0.2 0.2 0.35 0.23 0.02 3) Number of monthly absences of Juan Dela Cruz based on his previous records of absences as presented in the probability distribution below. Number of Absences (X) 3 4 5 6 Percent (Px) 25% 30% 30% 15% 4) The number of computers sold per day at a local computer store, along with its corresponding probabilities, is shown in the table below. Number of Computer Sold Probability P(x) (X) 0 0.1 2 0.2 5 0.3 7 0.2 9 0.25) The number of inquiries received per day by the office of Admission in SHS X last enrolment is shown below. Number of Inquiries (X) Probability P(x) 22 0.08 25 0.19 26 0.36 28 0.25 29 0.07 30 0.05 IV. RUBRIC FOR SCORING 5 4 3 2 1 Solutions are Solutions are Solutions are NOT | Solutions are NOT Solutions are accurate with accurate but so accurate with so accurate with totally incorrect correct incorrect irrelevant no interpretation interpretation interpretation interpretation at all V. ANSWER KEY Standard Deviation = 1.93 Standard Deviation = 2.88 Variance = 3.74 Variance = 8.29