Alan collects data about the students in his class. He records their hair color and whether they have freckles. His results are shown in the table below. Category Brown Hair Blonde Hair Red Hair Freckles 4 5 4 No Freckles 7 4 1 Find each probability. P(freckles) P(blonde hair or red hair) P(freckles and brown hair) P(no freckles|red hair)

Question

Alan collects data about the students in his class. He records their hair color and whether they have freckles. His results are shown in the table below. Category Brown Hair Blonde Hair Red Hair Freckles 4 5 4 No Freckles 7 4 1 Find each probability. P(freckles) P(blonde hair or red hair) P(freckles and brown hair) P(no freckles|red hair)

Answer 1

To find the probability of an event, we divide the number of favorable outcomes by the total possible outcomes.

P(freckles) = Number of students with freckles / Total number of students = (4 + 5 + 4) / (4 + 5 + 4 + 7 + 4 + 1) = 13 / 25

P(blonde hair or red hair) = Number of students with blonde or red hair / Total number of students = (5 + 4 + 4 + 1) / (4 + 5 + 4 + 7 + 4 + 1) = 14 / 25

P(freckles and brown hair) = Number of students with freckles and brown hair / Total number of students = 4 / 25

P(no freckles|red hair) = Number of students with red hair and no freckles / Total number of students with red hair = 1 / (4 + 1) = 1 / 5