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3 years ago

8

At the beginning of year 1, Amanda invests $800 at an annual compound interest rate of 5%. She makes no deposits or withdrawals

from the account.
Which explicit formula can be used to find the account's balance at the beginning of year 5? What is the balance?

1 answer:

VARVARA [1.3K]3 years ago

8 0

Answer:

its A my guy did it on apex 972.41

Step-by-step explanation:

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Exhibit: Department Store.

aalyn [17]

Answer:

Step-by-step explanation:

Considering the central limit theorem, the distribution is normal since the number of samples is large.

Confidence interval is written in the form,

(Sample mean - margin of error, sample mean + margin of error)

The sample mean, x is the point estimate for the population mean.

Confidence interval = mean ± z × σ/√n

Where

σ = population standard Deviation

σ/√n = sample standard deviation

Confidence interval = x ± z × σ/√n

1) x = $75

σ = $24

To determine the z score, we subtract the confidence level from 100% to get α

α = 1 - 0.96 = 0.04

α/2 = 0.04/2 = 0.02

This is the area in each tail. Since we want the area in the middle, it becomes

1 - 0.02 = 0.98

The z score corresponding to the area on the z table is 2.05. Thus, confidence level of 96% is 2.05

Confidence interval = 75 ± 2.05 × 24/√64

= 75 ± 2.05 × 3

= 75 ± 6.15

The lower end of the confidence interval is

75 - 6.15 = 68.85

The upper end of the confidence interval is

75 + 6.15 = 81.15

2) n = 400

x = $75

σ = $24

z = 2.05

Confidence interval = 75 ± 2.05 × 24/√400

= 75 ± 2.05 × 1.2

= 75 ± 2.46

The lower bound of the confidence interval is

75 - 2.46 = 72.54

The upper bound of the confidence interval is

75 + 2.46 = 77.46

3) n = 400

x = $200

σ = $80

The z score corresponding to the confidence level of 94% is 1.88

z = 1.88

Confidence interval = 200 ± 1.88 × 80/√400

= 200 ± 1.88 × 4

= 200 ± 7.52

Margin of error = 7.52

7 0

3 years ago

A box contains 2 plain pencils and 2 pens. A second box contains 7 color pencils and 3 crayons. One item from each box is chosen

photoshop1234 [79]

In the box containing the 2 plain pencils and 2 pens, there would be a 50% chance of getting a pen. In the other box containing 7 color pencils and 3 crayons there would be a 30% chance of getting a crayon.

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4 years ago

Keisha is solving the equation 7^x=9.

olganol [36]

$\bf \textit{Logarithm of exponentials}\\\\
log_a\left( x^ b \right)\implies b\cdot log_a(x)\\\\
-------------------------------\\\\
7^x=9\implies \boxed{log(7^x)=log(9)}\implies x\cdot log(7)=log(9)
\\\\\\
x=\cfrac{log(9)}{log(7)}$

3 0

3 years ago

Two fifths of the children in the nursery were boys. What was the ratio of boys to girls in the nursery?

Shtirlitz [24]

The answer would be 2:3

6 0

4 years ago

(High points) please solve with explanation

AysviL [449]

Answer:

The area and the perimeter of the picture are:

<u>Area = 160 cm^2</u>
<u>Perimeter = 67.31 cm</u>

Step-by-step explanation:

To find the area of that figure, you can find the area how if it was a rectangle and next subtract the area of the triangle in the upper part. The area of a rectangle could be found by the next formula:

Area of a rectangle = base * height

As you can see in the picture, the base is 16 cm and the height is 12 cm, then we replace in the formula:

Area of a rectangle = 16 cm * 12 cm
Area of a rectangle = 192 cm^2

Now, we calculate the area of the triangle to subtract to the area we found and obtain the real area, the formula to obtain the area of a triangle is:

Area of a triangle = (base * height) / 2

The height of the triangle is 8 cm, and the base is 8 cm too, because you subtract to the base of the rectangle (16 cm) the measurements in the upper part (16 - 4 - 4 = 8), Now, we replace in the formula:

Area of a triangle = (8 cm * 8 cm) / 2
Area of a triangle = (64 cm^2) / 2
Area of a triangle = 32 cm^2

We subtract to the found area:

Area of the picture = 192 cm^2 - 32 cm^2
<u>Area of the picture = 160 cm^2</u>

To find the perimeter, you must add all the sides of the picture, but, as you can see, there is a side that doesn't have the measurent, this is the hypotenuse of the triangle used before, but how we know the other sides, we can use Pythagorean theorem:

$a^{2}+b^{2}=c^{2}$

Where:

a = Opposite leg (8 cm)
b = Adjacent leg (8 cm)

So, we replace in the theorem:

$a^{2}+b^{2}=c^{2}$

$(8 cm)^{2}+(8cm)^{2}=c^{2}$ (and we clear c)
$\sqrt{(8 cm)^{2}+(8cm)^{2}} =c$
$\sqrt{64 cm^{2}+64cm^{2}} =c$
$\sqrt{128cm^{2}} =c$
c = 11.3137085 cm
c ≅ 11.31 cm

At last, we add all the sides of the picture begining by the base and going by the left side:

Perimeter of the picture = 16 cm + 12 cm + 4 cm + 11.31 cm + 8 cm + 4 cm + 12 cm
<u>Perimeter of the picture = 67.31 cm approximately</u>.

7 0

3 years ago