Which of the following variables are best thought of as cont

Which of the following variables are best thought of as continuous, which discrete?

(a) The number of your fellow classmates who have used the World Wide Web for information on Seasonal Affective Disorder

Discrete or Continuous

(b) The time for a participant to identify the color of the letters when the word red is shown in green letters on a computer screen

Discrete or Continuous

(c) The number of damaged chromosomes on a petri dish following irradiation

Discrete or Continuous

(d) The temperature of a burrito served to a customer in a local Mexican restaurant

Discrete or Continuous

Solution

Discrete refers to the distinct values like 1,2,3,4,............n ; where n is an integer.We cannot say 1.2 or 152.67 as discrete values.

Continuous refers to the continuous values like 1, 1.1, 1.2, 1.3,............n ; where n is a real number

(a) Discrete

since the no of fellow classmates are integers.There cannot be a situation where the no of classmates is 100.5 or 56.32.It will be either 100 or 56.

(b) Continuous

since for example say, the time taken can be 5 minutes or 5.6 minutes( 5 minutes 6 seconds)

(c) Discrete

since the no of damaged chromosomes has to be an integer.It cannot be 12.5 or 25.3.It can be either 12 or 25.

(d) Continuous

The temperature can be 15 degree celsius or say 15.9 degree celsius.So the values are not discrete.The temperature will decrease in the manner say 15, 14.9, 14.8, 14.7, ..... 12, 11.9,, 11.8, .........,0.2, 0.1, 0