determine the probability that blue sold had pacaging style 1

Question

                                      pkg 1           pkg2

blue                                215               148

red                                   89                 70

purple                               367              292

 

using the relative frequency of occurrence approach

 

what is the probability that blue sold was red

what is the joint probability that blue sold was blue and had packaging style 2

calculate the probability that blue chosen from those sold with packaging style 2 would be purple

Answer 1

Imagine that a total of 363 blues were sold (sum of pkg1 and pkg1).  The relative frequency of occurence is 215 / 363 for package 1 and 148 / 263.

 

(since blue only comes in 2 package styles, the sum must be 1)

 

p(blue) = 215 / 363 = 0.593