Discrete Random Variables Intro - Number of Siblings-2

Name: Wendi Maqueda Week 5: How many siblings do you have? Let X = the number of siblings. Suppose we choose someone from the class at random. X 1 2 3 4 5 6 7 8+ Probability 0.10 0.3 0.25 0.10  0.05  0.10 0.05 0.05 1. Is X a categorical or quantitative variable? Why? X is a categorical variable as it does not hold any value. 2. Are all the probabilities between 0 and 1? Yes, all of the are between 0 and 1 3. What do you get when you add all the probabilities? Show your work. 0.10+0.3+0.25+0.10+0.05+0.10+0.05+0.10+0.05+0.05= 1 4. Is 5.7167 a possible value for X ? Explain. No, it must be a solid number because there can’t be a decimal for a person. 5. Describe in words what P ( X ≥ 3 ) and then find P ( X ≥ 3 ) . ‘x is greater than or equal to 3 ‘ P(0.6 >/ 3) 6. Describe in words what P ( X > 3 ) and then find P ( X > 3 ) . ‘x is greater than 3’ P(0.35 > 3) Let Y = the time (minutes) it takes a randomly selected student to run a mile. Count up the number of siblings in your family (including yourself). Be sure to include all your stepbrothers/stepsisters and half-brothers/half-sisters. Input your answer in a blank row in the first column of the class shared spreadsheet: Sibling Activity Spreadsheet