Since in this case we are
only using the variance of the sample and not the variance of the real population,
therefore we use the t statistic. The formula for the confidence interval is:
<span>CI = X ± t * s / sqrt(n) ---> 1</span>
Where,
X = the sample mean = 84
t = the t score which is
obtained in the standard distribution tables at 95% confidence level
s = sample variance = 12.25
n = number of samples = 49
From the table at 95%
confidence interval and degrees of freedom of 48 (DOF = n -1), the value of t
is around:
t = 1.68
Therefore substituting the
given values to equation 1:
CI = 84 ± 1.68 * 12.25 /
sqrt(49)
CI = 84 ± 2.94
CI = 81.06, 86.94
<span>Therefore at 95% confidence
level, the scores is from 81 to 87.</span>
Note: You missed to add the dot plots chart. As I found the chart after a little research. Thus, I am attaching it and based on that dot plot chart I am solving the question which anyways would clear you concept.
Answer:
'There are about 2 more students in each class at Oak Middle School than at Poplar Middle School' is the correct statement.
Step-by-step explanation:
From the diagram, it is clear that
The data set containing Poplar Middle School:
20 20 20 21 21 21 21 21 22 22 22 22 22 22 22 23 23 23 23 24
The mean of a data set is the sum of the terms divided by the total number of terms. Using math notation we have:
The data set containing Oak Middle School:
20 21 21 22 22 23 23 23 23 24 24 24 25 25 26 26 27 27 28 29
The mean of a data set is the sum of the terms divided by the total number of terms. Using math notation we have:
So, the difference in mean will be:
Therefore, 'there are about 2 more students in each class at Oak Middle School than at Poplar Middle School' is the correct statement.
Answer:
8.125% is the answer
Step-by-step explanation:
steps in picture, to help you better understand
<span><u>3x + 8 = 26 + x</u>
The first thing you need to do is understand what you're looking for ...
what a 'solution' means, what it looks like, and how you even know
when you have it. I'm not sure you're there yet.
The 'answer' or the 'solution' to the problem is a number. It's the number
that 'x' must be in order for that line at the top to be a true statement. There's
only one possibility.
To find it, you can do anything you want to either side of the problem, as long as
you do exactly the same thing to the other side too. With that ability, here's how
to 'figure out the problem', and find the answer:
The original problem: </span><span><u>3x + 8 = 26 + x</u>
Subtract 8 from each side:
3x = 18 + x
Subtract 'x' from each side:
2x = 18
Divide each side by 2 :
<u>x = 9 </u> .
That's what the answer looks like, and that's what the answer is.
' 9 ' is the ONLY number you can write in place of 'x' in the problem,
and have the problem read true.
I'll show you what I mean. Let's take the original problem
</span><span> <u><span>3x + 8 = 26 + x
</span></u><span>and let's write ' 2 ' wherever we see 'x' :
3 (2) + 8 = 26 + 2
3 (2) means 3 times 2, and that's 6 .
So now we have
6 + 8 = 26 + 2
Do the addition on each side, and we have
14 = 28 .
That's nonsense. 14 is not equal to 28 . The reason that happened
is because we put the wrong number in place of 'x' . When we put the
correct number in place of 'x', the left side will be equal to the right side.
To 'figure out the problem' means to find out what that number must be.
For this particular problem, it's 9 .
</span><u><span /></u>
</span>
M / k = x.....multiply both sides by k. eliminating the k on the left side
m = xk <==
