Answer:
A. 
Step-by-step explanation:
We want to find the Z-score of
if the population mean is
,and the population standard deviation is
.
We use the formula:

We substitute the values to obtain:



The correct answer is A.
2 negatives can be converted to a plus sign. -(-x) can be +x or just x.
-54--23
-54+23
<u>23-54=-31</u>
78--4
<u>78+4=82</u>
-48/-6
Now let's pause fer a sec. When a negative is being divided by another negative, the quotient(answer to division problem) becomes a positive.
<u>-48/-6=8</u>
<u></u>
<u>50*-4=-200</u>
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hope it helps
Answer:
25/4 75/8
25/4= 6.25
and 75/8= 9.375
and 9.375/6.25 = 1.5
Step-by-step explanation:
Sn=sum of the n terms of the geometric sequence.
a= the first term
r=the common ratio
n=numbers of terms.
Sn=a[(1-r^n)/(1-r)]
In this case:
a=-3
r=a₂/a₁=15/-3=-5
n=9
S₉=-3[(1-(-5)⁹) / (1-(-5))=
S₉=-3(1+1953125)/6)=
S₉=-3(1953126/6)=
S₉=-3(325521)
S₉=-976563
Answer: A. -976563