d = 3 , a₁₂ = 40 and S
= 7775
In an arithmetic sequence the nth term and sum to n terms are
<h3>• a
= a₁ + (n-1)d</h3><h3>• S
=
[2a + (n-1)d]</h3><h3>
where d is the common difference</h3><h3>a₆ = a₁ + 5d = 22 ⇒ 7 + 5d = 22 ⇒ 5d = 15 ⇔ d = 3</h3><h3>a₁₂ = 7 + 11d = 7 +( 11× 3) = 7 + 33 = 40</h3><h3>S₁₀₀ =
[(2×7) +(99×3)</h3><h3> = 25(14 + 297) = 25(311)= 7775</h3>
(13 + 20) + 15 = 13 + (20 + 15)
Given diameter 2cm
Find the area of a circle
the formula for area of a circle
A = pi r^2
the diameter is the radius times two
so to find the radius given the diameter 2/2 = 1
radius is 1cm
pi is ~3.14
A = (3.14) * (1)^2
A = (3.14) * 1
A = 3.14
Hope this helps :)
Hello There!
To find the mean, add up all the numbers and divide according to how many numbers there are. The mean for this set would be <em>"9"</em>
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To find the median, place the numbers in value order and find the middle. if there is no middle, add up the two numbers in middle and divide by 2. In this set, the median would be <em>"8.5"</em>
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To find the mode or modal value, it is best to put the numbers in order. Then count how many of each number. A number that appears most often is the mode. In this set, there would be no mode.
The range of a set of data is the difference between the highest and lowest values in the set. In this set, the range would be <em>"12"</em>
