The answer is B) The initial number of bacteria is 57, and the growth rate is 31% per hour.
The expression shown is an <em>exponential expression</em>. An exponential expression usually takes the form , as this one does. A represents the <em>initial value</em>, in this case-the initial number of bacteria. B represents the <em>growth rate</em>. When it is an increasing growth rate, it will begin with 1, because it will have everything it had before, plus the percent increase, the decimal portion. In this case, a=57, and b=0.31.
Hope this makes sense!
Answer:
a) 0.2416
b) 0.4172
c) 0.0253
Step-by-step explanation:
Since the result of the test should be independent of the time , then the that the test number of times that test proves correct is independent of the days the river is correct .
denoting event a A=the test proves correct and B=the river is polluted
a) the test indicates pollution when
- the river is polluted and the test is correct
- the river is not polluted and the test fails
then
P(test indicates pollution)= P(A)*P(B)+ (1-P(A))*(1-P(B)) = 0.12*0.84+0.88*0.16 = 0.2416
b) according to Bayes
P(A∩B)= P(A/B)*P(B) → P(A/B)=P(A∩B)/P(B)
then
P(pollution exists/test indicates pollution)=P(A∩B)/P(B) = 0.84*0.12 / 0.2416 = 0.4172
c) since
P(test indicates no pollution)= P(A)*(1-P(B))+ (1-P(A))*P(B) = 0.84*0.88+ 0.16*0.12 = 0.7584
the rate of false positives is
P(river is polluted/test indicates no pollution) = 0.12*0.16 / 0.7584 = 0.0253
Answer: See below
Step-by-step explanation:
A)
Multiply both sides by -1 and reverse the inequality:
B)
Answer: 1,000 times longer
Step-by-step explanation: Dino have been extinct for about 60 million years ago, and Neanderthals have been extinct for about 40,000 years.
60,000,000 divided by 40,000 is 1500 so 1000 times longer (sorry if im wrong i'm new)