Question

a. In a class of 50 students, 28 are girls and 22 are boys. On a sectional test, 10 girls and 7 boys obtained grade A. Four girls and 9 boys achieved grade B. Another 8 girls and 6 boys earned grade C. The remaining students received grade F. Use this information to answer the questions following: i) What is the probability of choosing a grade A student. Interpret the result (2pts) ii) What is the probability of choosing a boy who has a grade C or better. Interpret the result (4pts) iii) What is the probability of selecting a grade F student. Interpret the result (4pts) iv) Draw the venn diagram given that event A = choosing a boy, and event B = choosing a grade A student or grade B student. Interpret the result (6pts) v)Questiontheinformationinquestion4(iv)tocalculatep(AorB).Interprettheresult (6pts) Using a 52 deck of playing cards, Event A = picking a picture card (Jack, Queen, or King), and Event B = b. picking a Diamond card, or an even number Spade card (2, 4, 6, 8, 10). Use the probability addition rule to find p (A or B) (12pts)

Answer 1

1)

N= 50, 22 boys & 28 girls

Grade A 7 boys & 10 girls

Grade B 9 boys & 4 girls

Grade C 6 boys & 8 girls

Grade F 0 boys & 6 girls

A) probability of choosing grade A Student

= (7+10)/(50)

= 0.34

B) probability of choosing a boy who has a grade C or better

= (7+9+6)/ 50

= 22/50

= 0.44

C) probability of selecting grade F student

= 6/ 50

= 0.12

D)

2)

P(A) = 12/52

Number of diamond cards = 13

Even number spade cards = 5

P(B) = 18/52

P(A n B) = 3/52

Probability addition rule

P( A U B) = P(A) + P(B) - P(A n B)

= 12/52 + 18/52 - 3/52

= 27/52

= 0.5192