My daughter needs help with math

A population is estimated to have a standard deviation of 9. We want to estimate the population mean within 2, with a 99% level

cupoosta [38]

Answer:

The sample required is $n = 135$

Step-by-step explanation:

From the question we are told that

The standard deviation is $\sigma = 9$

The margin of error is $E = 2$

Given that the confidence level is 99% then the level of significance is mathematically evaluated as

$\alpha = 100-99$

$\alpha = 1 \%$

$\alpha = 0.01$

Next we will obtain the critical value $\frac{\alpha }{2}$ from the normal distribution table(reference math dot armstrong dot edu) , the value is

$Z_{\frac{\alpha }{2} } = Z_{\frac{0.05 }{2} } = 2.58$

The sample size is mathematically represented as

$n = [ \frac{Z_{\frac{\alpha }{2} } * \sigma }{E} ]^2$

substituting values

$n = [ \frac{ 2.58 * 9 }{2} ]^2$

$n = 135$

3 0

3 years ago

Jaffrey was offered a job at $950 per month with a $22 increase every month for the first year. How much money can he make in th

iogann1982 [59]

Answer:

Jaffrey will end up making $1214 in the first year

Step-by-step explanation:

950 + 12(22) = ?

first lets find out what 12 * 22 =?

12 * 22 = 264

now lets add 264 to 950

264 + 950 = 1214

5 0

3 years ago

NO LINKS!!! Part 2: Find the Lateral Area, Total Surface Area, and Volume. Round your answer to two decimal places.

slava [35]

Answer:

<h3><u>Question 7</u></h3>

<u>Lateral Surface Area</u>

The bases of a triangular prism are the triangles.

Therefore, the Lateral Surface Area (L.A.) is the total surface area excluding the areas of the triangles (bases).

$\implies \sf L.A.=2(10 \times 6)+(3 \times 6)=138\:\:m^2$

<u>Total Surface Area</u>

Area of the isosceles triangle:

$\implies \sf A=\dfrac{1}{2}\times base \times height=\dfrac{1}{2}\cdot3 \cdot \sqrt{10^2-1.5^2}=\dfrac{3\sqrt{391}}{4}\:m^2$

Total surface area:

$\implies \sf T.A.=2\:bases+L.A.=2\left(\dfrac{3\sqrt{391}}{4}\right)+138=167.66\:\:m^2\:(2\:d.p.)$

<u>Volume</u>

$\sf \implies Vol.=area\:of\:base \times height=\left(\dfrac{3\sqrt{391}}{4}\right) \times 6=88.98\:\:m^3\:(2\:d.p.)$

<h3><u>Question 8</u></h3>

<u>Lateral Surface Area</u>

The bases of a hexagonal prism are the pentagons.

Therefore, the Lateral Surface Area (L.A.) is the total surface area excluding the areas of the pentagons (bases).

$\implies \sf L.A.=5(5 \times 6)=150\:\:cm^2$

<u>Total Surface Area</u>

Area of a pentagon:

$\sf A=\dfrac{1}{4}\sqrt{5(5+2\sqrt{5})}a^2$

where a is the side length.

Therefore:

$\implies \sf A=\dfrac{1}{4}\sqrt{5(5+2\sqrt{5})}\cdot 5^2=43.01\:\:cm^2\:(2\:d.p.)$

Total surface area:

$\sf \implies T.A.=2\:bases+L.A.=2(43.01)+150=236.02\:\:cm^2\:(2\:d.p.)$

<u>Volume</u>

$\sf \implies Vol.=area\:of\:base \times height=43.011193... \times 6=258.07\:\:cm^3\:(2\:d.p.)$

8 0

2 years ago

If 5 slices of pizza cost $5:50 how much does

kupik [55]

The first thing we must do for this case is to define variables.

We have then:

x: number of slices

y: total cost

We write the linear function that relates the variables.

We have then:

$y = (\frac{5.50}{5}) * x$

Then, we evaluate the number of slices to find the total cost.

-two slices cost:

We substitute x = 2 in the given equation:

$y = (\frac{5.50}{5}) * 2\\y = 2.2$

Answer:

two slices = 2.2 $

-ten slices cost:

We substitute x = 10 in the given equation:

$y = (\frac{5.50}{5}) * 10\\y = 11$

Answer:

ten slices = 11 $

-half a slice cost:

We substitute x = 1/2 in the given equation:

$y = (\frac{5.50}{5}) * \frac{1}{2}\\y = 0.55$

Answer:

half a slice = 0.55 $

6 0

3 years ago

Can u pls help me with this question

luda_lava [24]

The answer is $15.58

8 0

3 years ago

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My daughter needs help with math​

My daughter needs help with math