The formula for the standard error is this:
σM = σ / √N
where
σM is the standard error
σ is the standard deviation
N is the number of samples
So,
σM = 0.45 / √50
σM = 0.0636 or 6.36%
The standard error is 0.0636
The numbers of new CDs is 30 and the old CDs is 21.
To solve this problem, we have to write a system of equations in which we would know the numbers of each types of CD she bought.
<h3>System of Equations</h3>
This is used to solve a series or complex of word problems in which we can represent in a mathematical statements;
- Let n represents numbers of new CDs
- Let u represents numbers of old CDs
The equations can be represented as

Let's take equation (i)
Making n the subject of formula

we can put equation (iii) into equation (ii)

Let's put the value of u into equation (i)

From the calculations above, the numbers of new CDs is 30 and the old CDs is 21.
Learn more on system of equations here;
brainly.com/question/13729904
Answer:
3. Sides: Equilateral
Angles: Acute
4. Sides: Isosceles
Angles: Right
Step-by-step explanation:
3. Sides: Equilateral because in an equilateral triangle all sides are equal.
Angles: Acute because in an acute triangle all angles are acute.
4. Sides: Isosceles because in an isosceles triangle two legs are equal.
Angles: Right because in a right triangle, one angle is right.
Answer:
x = 0.447
Step-by-step explanation:
You need to use your graphing calculator for this.
In y=, put 13(0.25)^x in Y1 and put 7 in y2. Using 2nd trace, find the intersections.
The answer I got was x = 0.447.