Answer:
78
Step-by-step explanation:
do the equation backwards. 157 minus 1 equals 156, and 156 divided by 2 equals <u>78</u>. Hope this helps. pls mark brainliest
Answer:
a. correlation
b. inverse linear correlation exists If the higher the population of students lead to a decrease in test score,
c. yes
Step-by-step explanation:
a. Correlation is a measure of the amount of association existing between two variables.
b. For linear correlation, if points are plotted on a graph and all the points lie on a straight line, then perfect linear correlation is said to exist. When a straight line having a positive gradient can reasonably be drawn through points on a graph positive or direct linear correlation exists,
Similarly,when a straight line having a negative gradient can reasonably be drawn through points on a graph, negative or inverse linear correlation exists,
The results of this determination give values of r lying between +1 and −1, where +1 indicates perfect direct Positive linear correlation and −1 indicates perfect inverse correlation or Negative linear correlation and 0 indicates that no correlation exists.
If the higher the population of students lead to a decrease in test score, there will definitely be a negative correlation between class size and test score. i.e low class size result in high test score which consequently lead to high performance.
c. YES
A negative correlation means low class size result in high test score which consequently lead to better performance.
All you have to do is plug in.
x = 1 , y= 8
3x+5=y
3(1) + 5 = 8
3+5 = 8
8=8
They are both equal, yes. The coordinates work out in the equation. Both sides are equal so the coordinates work. The answer is yes.
Answer: Choice A
S9 = (9/2)*(2+26)
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The formula is
Sn = (n/2)*(a1+an)
where
Sn = sum of the first n terms (nth partial sum)
n = number of terms
a1 = first term
an = nth term
In this case,
n = 9
a1 = 2 (plug in n = 1 into the formula an = 3n-1 and simplify)
an = a9 = 26 (plug n = 9 into the formula an = 3n-1 and simplify)
So,
Sn = (n/2)*(a1+an)
S9 = (9/2)*(2+26)
will help us find the sum of the first 9 terms of this arithmetic sequence
