Answer:
X=2, Y=-15
Step-by-step explanation:
-7x+y=-19
-2x+3y=-19
------------------
-3(-7x+y)=-19
-2x+3y=-19
---------------------
21x-3y=57
-2x+3y=-19
---------------------
19x = 38
19x/19=38/19
x=2
now plug 2 into x of the second equation to get y=-15
Unfortunately, I can't do it on a graph here, but I will do it algebraically.
The solution on the graph will be the point of intersection of the two lines representing the equations.
y + 2.3 = 0.45x . . . . . (1)
-2y = 4.2x - 7.8 . . . . . (2)
From (2), y = 3.9 - 2.1x
substituting for y in (1), we have:
3.9 - 2.1x + 2.3 = 0.45x
2.55x = 6.2
x = 6.2/2.55 = 2.4
y = 3.9 - 2.1(2.4) = 3.9 - 5.04 = -1.2
Therefore, solution is (2.4, -1.2)
Answer:
A sample size of at least 228 must be needed.
Step-by-step explanation:
We are given that in the latest survey by the National Association of Colleges and Employers, the average starting salary was reported to be $61,238. Assume that the standard deviation is $3850.
And we have to find that what sample size do we need to have a margin of error equal to $500 with 95% confidence.
As we know that the Margin of error formula is given by;
<u>Margin of error</u> = 
where, 
= significance level = 1 - 0.95 = 0.05 and 
= 0.025.
= standard deviation = $3,850
n = sample size
<em>Also, at 0.025 significance level the z table gives critical value of 1.96.</em>
So, margin of error is ;
= 15.092
Squaring both sides we get,
n = 
= 227.8 ≈ 228
So, we must need at least a sample size of 228 to have a margin of error equal to $500 with 95% confidence.
None of thouse answers are corect
but if i was u i would pick d
Answer:
an=8n−14
Step-by-step explanation:
for an AP
where
a
1
=
the first term
d
=
the common difference
then we have
a
1
,
(
a
1
+
d
)
,
(
a
1
+
2
d
)
,
...
,
a
1
+
(
(
n
−
1
)
d
)
,
.
.
we are given the third term
10
=
a
1
+
2
d
−
−
(
1
)
and the fifth term
26
=
a
1
+
4
d
−
−
(
2
)
subtract
(
2
)
−
(
1
)
16
=
2
d
⇒
d
=
8
sub into
(
1
)
10
=
a
1
+
2
×
8
⇒
a
1
=
−
6
so the nth term
a
n
=
a
+
(
n
−
1
)
will be
a
n
=
−
6
+
8
(
n
−
1
)
a
n
=
8
n
−
14
