Answer:
1
8
4
−
3
3
−
2
3
+
2
−
1
0
+
6
18
x
4
−
3
x
3
−
2
x
3
+
x
2
−
10
+
6
18x4−3x3−2x3+x2−10+6
1
8
4
−
3
3
−
2
3
+
2
−
4
18
x
4
−
3
x
3
−
2
x
3
+
x
2
−
4
18x4−3x3−2x3+x2−4
2
Combine like terms
Solution
1
8
4
−
5
3
+
2
−
4
Step-by-step explanation:
15 abbabababababababababbababa
Answer:
Option B) 9.1
Step-by-step explanation:
We are given the following in the question:
Average score = 490.4
Standard deviation = 63.7
Sample size, n = 49
Formula:

Putting values, we get,
Standard error =

Thus, the correct answer is
Option B) 9.1
[-½, ¾]; use either "Substitution" or "Elimination" to do this, and you'll see that this answer is correct.