Answer:
The minimum sample size needed is 
. If n is a decimal number, it is rounded up to the next integer. 
is the standard deviation of the population.
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Z-table as such z has a p-value of 
.
That is z with a pvalue of 
, so Z = 1.645.
Now, find the margin of error M as such
In which is the standard deviation of the population and n is the size of the sample.
How large a sample must she select if she desires to be 90% confident that her estimate is within 4 ounces of the true mean?
A sample of n is needed, and n is found when M = 4. So
The minimum sample size needed is . If n is a decimal number, it is rounded up to the next integer. is the standard deviation of the population.
Move the decimal places, the answer is 6.7 x 10^6
Since there are two events happening simultaneously (windy and no sun), we can apply the concept of conditional probability here.
P(A|B) = P(A∩B)/P(B)
where it means that given B is happening, the probability that A is happening as well is the ratio of the chance for A and B to happen simultaneously over the chance of B to happen.
For our case, this can be interpreted as
P(A|B): it is the probability that it is windy (A) GIVEN that there is no sun (B)
P(A∩B) : chance of wind and no sun
P(B) : chance that there is no sun tomorrow
The chance of P(A∩B) is already given as 20% or 0.20. Since there is 10% or 0.10 chance of sun, then chances of having no sun tomorrow is (1-0.10) = 0.90.
Thus, we have P(A|B) = 0.2/0.9 ≈ 0.22 or 22%.
So, answer is B: 22%<span>.</span>
Answer:
see attached
Step-by-step explanation:
I find it convenient to let a graphing calculator draw the graph (attached).
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If you're drawing the graph by hand, there are a couple of strategies that can be useful.
The first equation is almost in slope-intercept form. Dividing it by 2 will put it in that form:
y = 2x -4
This tells you that the y-intercept, (0, -4) is a point on the graph, as is the point that is up 2 and right 1 from there: (1, -2). A line through those points completes the graph.
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The second equation is in standard form, so the x- and y-intercepts are easily found. One way to do that is to divide by the constant on the right to get ...
x/2 +y/3 = 1
The denominators of the x-term and the y-term are the x-intercept and the y-intercept, respectively. If that is too mind-bending, you can simply set x=0 to find the y-intercept:
0 +2y = 6
y = 6/2 = 3
and set y=0 to find the x-intercept
3x +0 = 6
x = 6/3 = 2
Plot the intercepts and draw the line through them for the graph of this equation.
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Here, we have suggested graphing strategies that don't involve a lot of manipulation of the equations. The idea is to get there as quickly as possible with a minimum of mistakes.
If TU is 7.5 and UC is 17.5, TV = 25 because you just add the two together
