Question

mr. mcelroy enjoys listening to his mp3 player, which has 2,000 songs in five different genres of music. he took a sample of the number of each type of song it played on two different one - hour sessions when it was set to play a ran mix. the results are displayed in the table below. what is a good prediction for the number of rock songs mr. mcelro has on his mp3 player?
listening samples from mr. mcelroy’s mp3 player

	sample 1		sample 2
country	5	country	3
pop	4	pop	3
classical	3	classical	5
jazz	2	jazz	4
rock	6	rock	5

225
550
1100
1667

Explanation:

Step1: Calculate total sample 1 songs

$5 + 4 + 3 + 2 + 6 = 20$

Step2: Calculate total sample 2 songs

$3 + 3 + 5 + 4 + 5 = 20$

Step3: Total rock songs in samples

$6 + 5 = 11$

Step4: Total songs in both samples

$20 + 20 = 40$

Step5: Find rock song proportion

$\frac{11}{40} = 0.275$

Step6: Predict total rock songs

$2000 \times 0.275 = 550$

Answer:

B. 550