Question

A bag contains 45 marbles of various colors. Jon draws 60 times, each time replacing the marble before drawing again. He gets a total of 12 blue marbles.

Which is best prediction of how many blue marbles are in the bag?

A.
5

B.
9

C.
12

D.
15

Answer 1

need help

Answer 2

i need help

Answer 3

This is a case of observed probability. Jon mixes up the marbles in the bag, and then 60 times draws 1 marble. Every time he draws a marble, he puts the marble back into the bag and stirs up the marbles. The result of these 60 draws was 12 blue marbles in 60 tries.

Thus, the observed probability is \[\frac{ 12 successes }{ 60 tries }\]

or 12/12 successes in 60/12 tries, or 1 success in 5 tries.

In other words, Jon will most probably draw a blue marble one time in five tries.

Answer 4

so answer is 5

Answer 5

right

Answer 6

Just one sec elijah

Answer 7

I'm afraid not. You, I assume, thought that @mathmale meant that it'd be 5, when he said "one in five times"?

Answer 8

Correct?

Answer 9

In this type of problem, probability is defined as

number of successes (that is, getting a blue marble)
p = ----------------------------------------------
total number of tries (draws)

and here that probability boils down to

12 blue marbles 12
p = ------------------- = ---- = ? (reduce 12/60).
= 60 draws 60

Answer 10

thank u..