RANDOM VARIABLE

Which of the following statements is true?

• A random variable is a quantity having a numerical value for each member of a group, especially one whose values occur according to a frequency distribution.

• A random variable is a quantity having a value for each member of a group, especially one whose values occur according to a frequency distribution.

• A random variable is a quality having a numerical value for each member of a group, especially one whose values occur according to a frequency distribution.

State whether the variable is discrete or continuous. Use CAPITAL letters in typing your answer. The speed of a solar car.

(a)  

State whether the variable is discrete or continuous. Use CAPITAL letters in typing your answer. The height of a two-storey building

(a)  

State whether the variable is discrete or continuous. Use CAPITAL letters in typing your answer. The number of plates of pizza served by a restaurant each day.

(a)  

State whether the variable is discrete or continuous. Use CAPITAL letters in typing your answer. The number of senior high school students who will pursue the academic track

(a)  

State whether the variable is discrete or continuous. Use CAPITAL letters in typing your answer. The length of the building

(a)  

Which of the following random variables is continuous?

• the number of learning packets delivered in a day

• the number of bottled water sold in a day

• the amount of time it takes to conduct swab-test

Let X be the time it takes to finish a one-hour exam. What are the possible values of X (in hours)?

• $x\le1$

• $0\le x\le1$

• $0<x<1$

Observation: In a certain call center agency, an agent receives 10 to 25 calls in a 1-hour period. Let X be the number of calls an agent receives in 2 hours. What are the possible values of X?

• $10\le x\le25$

• $x=10,11,12,13,14,...,25$

• $x=10,11,12,13,14,...,50$

Experiment: Ask 50 shampoo users                                       Let X be the number of satisfied users.  What are the possible values of X?

•  $x\le50$ 

•  $x=1,2,3,4,5,...,50$ 

•  $x=0,1,2,3,4,...,50$