Answer:
25 questions
Step-by-step explanation:
84%*x = 21
-simplify-
0.84 *x = 21
Divide both sides by 0.84 than...
you get x = 25
Answer:
The standard deviation of the data set is
.
Step-by-step explanation:
The Standard Deviation is a measure of how spread out numbers are. Its symbol is σ (the greek letter sigma)
To find the standard deviation of the following data set

we use the following formula

Step 1: Find the mean
.
The mean of a data set is the sum of the terms divided by the total number of terms. Using math notation we have:


Step 2: Create the below table.
Step 3: Find the sum of numbers in the last column to get.

Step 4: Calculate σ using the above formula.

Let

Differentiating twice gives


When x = 0, we observe that y(0) = a₀ and y'(0) = a₁ can act as initial conditions.
Substitute these into the given differential equation:


Then the coefficients in the power series solution are governed by the recurrence relation,

Since the n-th coefficient depends on the (n - 2)-th coefficient, we split n into two cases.
• If n is even, then n = 2k for some integer k ≥ 0. Then




It should be easy enough to see that

• If n is odd, then n = 2k + 1 for some k ≥ 0. Then




so that

So, the overall series solution is

