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Evgesh-ka [11]
3 years ago
9

Find the sum of the first 18 terms of the arithmetic sequence whose nth term is an = 3n - 1.

Mathematics
1 answer:
vodka [1.7K]3 years ago
7 0

Answer:

495

Step-by-step explanation:

In order to find the sum of the first 18 terms you have to find the 18th term and the first term using the equation given.

a1=3(1)-1        a1=2

a18=3(18)-1   a18= 53

Then plug in 53 for an, 18 for n, and 2 in for a1 in the sum equation: Sn=n/2(a1+an)  

Sn=18/2(2+53)  Solve for sn= 495

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Select ALL the correct answers.
Marina CMI [18]

Answer:

The median of A is the same as the median of B.

The interquartile range of B is greater than the interquartile range of A.

Step-by-step explanation:

Given that:

A = number of runs allowed in first 9 games

A = {1, 4, 2, 2, 3, 1, 1, 2, 1}

Rearranging A : 1, 1, 1, 1, 2, 2, 2, 3, 4

Median A = 1/2(n + 1) th term

Median A = 1/2(10) = 5th term = 2

Q1 of A = 1/4(10) = 2.5th term = (1 + 1)/ 2 = 1

Q3 of A = 3/4(10) = 7.5th term = (2+3)/2 = 2.5

Interquartile range = Q3 - Q1 = 2.5 - 1 = 1.5

Number of runs allowed in 10th game = 9

B = {1, 4, 2, 2, 3, 1, 1, 2, 1, 9}

Rearranging B = 1, 1, 1, 1, 2, 2, 2, 3, 4, 9

Median A = 1/2(n + 1) th term

Median A = 1/2(11) = 5.5th term = (2+2)/2 = 2

Q1 of A = 1/4(11) = 2.75th tetm = (1 + 1)/ 2 = 1

Q3 of A = 3/4(11) = 8.25th term = (3+4)/2 = 3.5

Interquartile range = Q3 - Q1 = 3.5 - 1 = 2.5

Median A = 2 ; median B = 2

IQR B = 2.5 ; IQR A = 1.5 ; IQR B > IQR A

7 0
3 years ago
If I wanted to buy CD player and it cost $49.95 but I have a 5%tax what do I do?
alexgriva [62]

Answer:

$5.20

Step-by-step explanation:

4.95 + (0.05 x 4.95) = x

4.95 + 0.2475 = x

X= 5.1975

Rounds to $5.20

5 0
3 years ago
To represent the loss of 5 points on the stock market you could use
Veronika [31]
You could use a graph
5 0
3 years ago
Suppose the auction house from the preceding problem sold 200 tickets at $1 each, and had 16 prizes of $10 each. What is the new
Luda [366]
The answer is $0.8

200/160=1.25
200+160=360/1.25/160=200.8
so the answer is $0.8
8 0
4 years ago
Read 2 more answers
I need help with this.
almond37 [142]

Answer:

theoretical probability 1/2 or 50%

experimental probability 20/50 or 40%

8 0
4 years ago
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