.83
25 bus riding sophomores / 30 sophomores
Answer:
D)the time (in hours) a 4-year-old spends unsupervised per day
Step-by-step explanation:
Given that 4-year-olds in a certain country average 3 hours a day unsupervised and that most of the unsupervised children live in rural areas, considered safe
X - the time (in hours) a 4-year-old spends unsupervised per day
X is N(3,1.8)
Answer:
no
Step-by-step explanation:
Let f represent the fraction of C-14 remaining as a function of the time t in years. Since the half-life of C-14 is about 5570 years, we have ...
f = (1/2)^(t/5570)
Taking the log and solving for t, we get ...
log(f) = (t/5570)log(1/2)
5570·log(f)/log(1/2) = t
Filling in the given value for f, the value of t we get is ...
5570·log(0.65)/log(0.5) = t ≈ 3462
It appears the estimate of 4000 years is a bit high.
Answer:
Step-by-step explanation:
favorable events=x
total number of events=x+y
P=(favorable events)/(total number of events)=x/(x+y)
