Let R and B be the number of red and blue marbles respectively.
Then,
R+B = 36
R:B = 5:4
Therefore,
Ratio of red marbles = 5/9
Ratio of blue marbles = 4/9
This means,
R = 5/9*36 = 20 marbles
B = 4/9*36 = 16 marbles
If one blue marble is removed from the bag, the new B= 16-1 = 15 blue marbles and the new total of marbles in the bag = 36-1 = 35 marbles.
The new ratios are
R = 20/35 =4/7
B = 15/35 = 3/7
That is, R:B = 4:3
The reasoning of the student is wrong. When a marble is removed, both the number of blue marbles changes as well as the total of the marbles in the bag. In other words, both the values in the ratio reduce by 1.
Answer:
2.618 radians
Step-by-step explanation:
Answer:
<u>The z-score = -3.7 and p (-3.7) = 0.00011 or 0.011%</u>
Step-by-step explanation:
1. Let's review the information given to us to answer the question correctly:
Mean of time to finish a test = 60 minutes
Standard deviation of time to finish a test = 10 minutes
Time that a student finishes the test = 23 minutes
2. What is the z-score for the student?
z-score = (Time that a student finishes the test - Mean of time to finish a test)/Standard deviation of time to finish a test
Replacing with the real values:
z-score = (23 -60)/10 = -37/10 = -3.7
<u>z-score = -3.7 and p (-3.7) = 0.00011 or 0.011%</u>
