Answer:
740
Step-by-step explanation:
The n th term of an arithmetic series is
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Given a₃ = 7 and a₇ = (3 × 7) + 2 = 21 + 2 = 23 , then
a₁ + 2d = 7 → (1)
a₁ + 6d = 23 → (2)
Subtract (1) from (2) term by term
4d = 16 ( divide both sides by 4 )
d = 4
Substitute d = 4 into (1)
a₁ + 2(4) = 7
a₁ + 8 = 7 ( subtract 8 from both sides )
a₁ = - 1
The sum to n terms of an arithmetic series is
= 
[ 2a₁ + (n - 1)d ] , thus
= 
[ (2 × - 1) + (19 × 4) ]
= 10(- 2 + 76) = 10 × 74 = 740
Answer:
1/3
Step-by-step explanation:
The formula for computing the sum of an infinite geometric series is
where r is between -1 and 1 and 
is the common ratio, and 
is the first term of the series.
So let's plug in:
I multiplied bottom and top by 10.
I divided top and bottom by 3.
The sum is 1/3.
Based on the mean, standard deviation, and the graph, the indicated IQ score would be 115.
<h3>What is the indicated IQ score?</h3>
First, find the z value:
P(Z<z) = 1 - tail value
= 1 - 0.1587
= 0.8413
According to the z-value, this gives a value of:
z = 1
The indicated IQ score is:
= mean + z value z standard deviation
= 100 + 1 x 15
= 115
Find out more on normal distributions at brainly.com/question/4079902
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Step-by-step explanation:
???
what is the problem ? you don't know how to add, subtract or multiply yet ?
sum of 57 and 16 : 57 + 16 = 73
difference of 61 and 31 : 61 - 31 = 30
the product of the sum and the difference :
73 × 30 = 2190
