Answer:
a) The margin of error for a 90% confidence interval when n = 14 is 18.93.
b) The margin of error for a 90% confidence interval when n=28 is 12.88.
c) The margin of error for a 90% confidence interval when n = 45 is 10.02.
Step-by-step explanation:
The t-distribution is used to solve this question:
a) n = 14
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 14 - 1 = 13
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 13 degrees of freedom(y-axis) and a confidence level of
. So we have T = 1.7709
The margin of error is:

In which s is the standard deviation of the sample and n is the size of the sample.
The margin of error for a 90% confidence interval when n = 14 is 18.93.
b) n = 28
27 df, T = 1.7033

The margin of error for a 90% confidence interval when n=28 is 12.88.
c) The margin of error for a 90% confidence interval when n = 45 is
44 df, T = 1.6802

The margin of error for a 90% confidence interval when n = 45 is 10.02.
Answer:
Table C
Step-by-step explanation:
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
or 
Find the value of the constant of proportionality in each table
Table A
For
------>
For
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This table has different values of k
therefore
the table A does not represent a proportional relationship
Table B
For
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For
------>
For
------>
This table has different values of k
therefore
the table B does not represent a proportional relationship
Table C
For
------>
For
------>
For
------>
For
------>
This table has the same value of k
therefore
the table C represent a proportional relationship
Table D
For
------>
For
------>
For
------>
For
------>
This table has different values of k
therefore
the table D does not represent a proportional relationship

- Factor the indicated expression:

- Simplified the index the root and also the exponent using the number 2.

<h3><em><u>MissSpanish</u></em> </h3>
I would think the answer is -16
but that's is what i think