Multiply out the bracket and simplify 3(x+7)+2x
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The sum of the given series can be found by simplification of the number
of terms in the series.
- A is approximately <u>2020.022</u>
Reasons:
The given sequence is presented as follows;
A = 1011 + 337 + 337/2 + 1011/10 + 337/5 + ... + 1/2021
Therefore;
The n + 1 th term of the sequence, 1, 3, 6, 10, 15, ..., 2021 is given as follows;
Therefore, for the last term we have;
2 × 2043231 = n² + 3·n + 2
Which gives;
n² + 3·n + 2 - 2 × 2043231 = n² + 3·n - 4086460 = 0
Which gives, the number of terms, n = 2020
Which gives;
- A ≈ <u>2020.022</u>
Learn more about the sum of a series here:
We have been given that the ages of students in a school are normally distributed with a mean of 15 years and a standard deviation of 2 years.
We are asked to find the percentage of students that are between 14 and 18 years old.
First of all, we will find z-score corresponding to 14 and 18 using z-score formula.
Similarly, we will find the z-score corresponding to 18.
Now we will find the probability of getting a z-score between and
that is
.
Using normal distribution table, we will get:
Let us convert into percentage.
Therefore, approximately of the students are between 14 and 18 years old.