The sum of the first 20 terms of an arithmetic sequence with the 18th term of 8.1 and a common difference of 0.25 is 124.5
Given,
18th term of an arithmetic sequence = 8.1
Common difference = d = 0.25.
<h3>What is an arithmetic sequence?</h3>
The sequence in which the difference between the consecutive term is constant.
The nth term is denoted by:
a_n = a + ( n - 1 ) d
The sum of an arithmetic sequence:
S_n = n/2 [ 2a + ( n - 1 ) d ]
Find the 18th term of the sequence.
18th term = 8.1
d = 0.25
8.1 = a + ( 18 - 1 ) 0.25
8.1 = a + 17 x 0.25
8.1 = a + 4.25
a = 8.1 - 4.25
a = 3.85
Find the sum of 20 terms.
S_20 = 20 / 2 [ 2 x 3.85 + ( 20 - 1 ) 0.25 ]
= 10 [ 7.7 + 19 x 0.25 ]
= 10 [ 7.7 + 4.75 ]
= 10 x 12.45
= 124.5
Thus the sum of the first 20 terms of an arithmetic sequence with the 18th term of 8.1 and a common difference of 0.25 is 124.5
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Answer:
Lin likes Sunnyside High School
Step-by-step explanation:
The Mean Absolute Deviation (MAD) is a measure of how dispersed the values are, in this case the score of the teams. So, Sunnyside High School, with a low MAD, scores nearly the same amount of points in every game.
Answer: The speed of the bird when it flies against the wind would be 8 meters per second
A. The figure is a triangular pyramid. You can findits surface area by adding up the area of the three faces of the triangle and the area of the base. A derived formula also is used where the SA is equal to 12 times the perimeter of base times the slant height, added to that is the area of the base. The area of the square base is s^2. Its perimeter is 4s.
SA of Pyramid = 12*P*l + s^2
SA of Pyramid = 12*4s*l + 16^2
SA of Pyramid = 12*4(16)*(17) + (16)^2
SA of Pyramid = 11,008 square inches
b.) The formula for the SA of a cone is:
SA of cone = πr[r+√(h^2+r^2)]
SA of cone = π(3)[(3+√(8^2+3^2)]
SA of cone = 108.8 square inches
Answer: (0,-4)
explanation: write in vertex form and use this form to find the vertex ( h , k )
