Answer:
B. A sample in which the subjects themselves decide whether to be included in the study.
Step-by-step explanation:
In other words a voluntary response sample is a sample made up of volunteers o people who choose to be inlcuded.
Answer:
a
x
2
+
b
x
+
c
=
0
the formula for the roots is
x
=
−
b
±
√
b
2
−
4
a
c
2
a
(
1
)
Identify the values for
a
,
b
,
&
c
x
2
+
4
x
+
3
=
0
cmp
a
x
2
+
b
x
+
c
=
0
a
=
1
b
=
4
c
=
3
(
2
)
Substitute these numbers into eh formula
x
=
−
4
±
√
4
2
−
(
4
×
1
×
3
)
2
×
1
(
3
)
Carefully proceed and do the calculations
x
=
−
4
±
√
16
−
12
2
x
=
−
4
±
√
4
2
x
=
−
4
±
2
2
now calculate the two separate solutions
x
1
=
−
4
+
2
2
=
−
2
2
=
−
1
x
2
=
−
4
−
2
2
=
−
6
2
=
−
3
Answer link
Step-by-step explanation:
Answer:
Charles practiced for the relay race for D. 9 hours last week.
Step-by-step explanation:
First, I would find the ratios the ratios for converting hurdle to javelin and javelin to relay.
Hurdle : Javelin ; 5 : 1.5
Javelin : Relay ; 2.5 : 5 or 1 : 2
Next, find the factors compared to the original numbers for hurdle to javelin.
15 / 5 = 3
To find the amount of javelin time they did, multiply 1.5 by the factor we got, 3.
1.5 * 3 = 4.5
Finally, double 4.5, since Charles does twice as much relay than he does javelin.
4.5 * 2 = 9 hours
