Answer:
no enough evidence to draw up a conclusion
Step-by-step explanation:
Data:
let: 
= decay after 2 weeks
= decay after 16 weeks
Making the hypotheses:
Null hypothesis; 
the deviation = 0.05
the standard difference = 4
Conditions:
The normal distribution curve can be plotted on a graph and the plot shows that the distribution is a skewed distribution.
Then,
Therefore, it can be concluded that 0.1983 > 0.05. This presents our failure to reject the null hypothesis.
Thus, there is not enough evidence to conclude that polyester decays more in less than 2 weeks.
The correct answer is 60 cm
Answer for the first one is just 7/9, 28/36
Second one is 9/14, 3/4
For the third one you multiply 12.50 by 5 which gives you 62.5
Well, this problem is best solved by setting up a system of two linear equations.
A linear equation can be defined
y=mx+b
where
b=initial value (when x=0), and
m=rate of increase or decrease.
In the given example, the x-axis represents hour, and the y-axis, number of cells.
Chemical #1
initial value = b = 12000 cells
rate = m = -4000 / hr
The equation is therefore
y1=-4000x+12000......................(1)
Similarly, for chemical #2
initial value = b = 6000 cells
rate = m = -3000 / hr
The equation is therefore
y2=-3000x+6000 .......................(2)
The time the two will have an equal sized colony would represent the solution of the system of equations (1) and (2), i.e. when y1=y2
which means
-4000x+12000 = -3000x+6000
transpose and solve for x
4000x-3000x = 12000-6000
1000x=6000
x=6 hours.
At 6 hours from the start,
y=-4000x+12000 = -4000*6+12000 = -24000+12000 = -12000 cells
So the solution is x=6, y=-12000, or (6,-12000)
Physical interpretation
Since cells cannot have a negative number, the two are actually equal before six hours, when they are both zero.
Case 1: y=0 when x=3
Case 2: y=0 when x=2
Therefore, after three hours, both trials will have zero cells.
You have to judge whether to give the mathematical solution (x=6,y=-12000) or the physical interpretation (x=3, y=0) as the answer.
Which statements, do you have any pics of the statements?
