Answer:
25%
Step-by-step explanation:
You have 60 total, 30 on the track team would be 50%, but there is only 15 on the track them, you cut the 50% in half again which gives 25%.
13: multiply the amount by the tax rate (to make a percent a decimal move the decimal point 2 places to the left) and add the original amount and the taxed amount together. For 12 do above but then multiply the total by the tip rate and add together (basically the same as the tax again) :) I hope this helps
Answer:
0.0274
Step-by-step explanation:
The mean is
and the standard deviation is 
Calculate
for 
If
then 
and

Use table for normal distribution probabilities to get that

Answer:
(a)3-2=1 (b) 4-3=1 (c) 12-1-1=10