Answer:
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The population proportion have the following distribution
Solution to the problem
We assume for this case a confidence level of 95%. In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by
and
. And the critical value would be given by:

The confidence interval for the mean is given by the following formula:
The margin of error for the proportion interval is given by this formula:
(a)
And if we replace the values obtained we got this:
Answer:
22.44
Step-by-step explanation:
If it’s the midpoint, just multiply it by 2 giving you full length
Answer:
169
Step-by-step explanation:
Given data
The function is
5x^2+7x=6
rearrange
5x2+7x-6=0
From the above expression, we can see that
a=5
b=7
c=-6
Substitute into the expression b^2-4ac
=7^2-4*5*-6
= 49-(-120)
=49+120
=169
Hence the answer is 169
Answer:
C
Step-by-step explanation:
In order to write the equation, you need to identify the slope and y-intercept.
1) the y intercept is what y is when x=0. According to the table, it is -2.
2) the slope is the change in the y values over the change in the x values. Notice that the y values are increasing by one for every increase in 1 in the x values, so the slope is 1/1 or 1.
3) we can then put those values into slope-intercept form which is y=mx+b where m is the slope and b is the intercept.
4) so the equation is y=(1)x-2 or y=x-2 (they are the same)
Rachel and her sister Fran together can paint the living room in
hours
Given that
Rachel can paint half of the living room in 1 hour
Fran can paint
th part of the living room in 1 hour
Let's assume together they paint the living room in x hours
⇒ together they can paint
th part of the living room in 1 hour
By proportions,
⇒
+
=
{using operation proportions and addition}
⇒
=
⇒x=
⇒ together they can paint
th part of the living room in 1 hour
It means, Rachel and her sister Fran together can paint the living room in
hours
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