Solve the expression: 12+18 divided by 3x2=

2. To estimate the mean age for a population of 4000 employees, a simple random sample of 40 employees is selected. a. Would you

ANEK [815]

Answer:

Step-by-step explanation:

a.

Size of the population, N = 4000

Size of the sample, n = 40

n/N = 40/4000 = 0.01

0.01 is less than 0.05 and hence we would not us the finite population correction factor in calculating the standard error of the mean.

b.

Population standard deviation is σ = 8.2

So, the standard error of x’ using the finite population correction factor is give by

σ(x’) = √[(N - n)/(N - 1)] x (sigma/√n)

σ(x’) = √[(4000 - 40)/(4000 - 1)] x (8.2/√40)

σ(x’) = 1.29

Standard error of x’ without using the finite population correction factor is

σ(x’) = σ/√n

σ(x’) = 8.2/√40 = 1.2965

There is little difference between the two values of the standard error. So we can ignore the population correction factor.

c.

Let the population mean be μ

Probability that the sample mean will be within =-2 of the population mean is

P(μ– 2 < x’ < μ + 2)

At x’ = μ – 2 , we have

z = (μ – 2 – μ)/1.2965

z = -1.54

at x’ = μ + 2, we have

z = (μ + 2 – μ)/1.2965

z = 1.54

So the required probability is

P(μ – 2 < x’ < μ + 2) = p(-1.54< z < 1.54)

P(μ – 2 < x’ < μ + 2) = p(z < 1.54) – p(z < -1.54)

P(μ – 2 < x’ < μ + 2) = 0.9382 – 0.0618

P(μ – 2 < x’ < μ + 2) = 0.8764

7 0

3 years ago

A cell tower is located at and transmits a circular signal that covers three major cities. The three cities are located on the c

Lelu [443]

Answer:

$(x+8)^2 +(y-4)^2 = 25$

Step-by-step explanation:

Assuming this complete problem: "A cell tower is located at (-8, 4) and transmits a circular signal that covers three major cities. The three cities are located on the circle and have the following coordinates: G (-4, 7), H (-13, 4), and I (-8, -1). Find the equation of the circle"

For this case the generla equation for the circle is given by:

$(x-h)^2 +(y-k)^2 = r^2$

From the info we know that the tower is located at (-8, 4) so then h = -8 and k = 4, so then we need to find the radius. So we have the equation like this: $(x+8)^2 +(y-4)^2 = r^2$

If the 3 points are on the circle then satisfy the equation. We can use the first point (-4,7) and if we replace we can find the value for $r^2$

$(-4+8)^2 +(7-4)^2 =25= r^2$

So then $r = \sqrt{25}=5$

And if we replace the second point we got this:

$(-13+8)^2 +(4-4)^2 = 25 =r^2$

And for the third point we have:

$(-8+8)^2 +(-1-4)^2 = 25 =r^2$

And we got the same result.

So then our final equation is given:

$(x+8)^2 +(y-4)^2 = 25$

4 0

3 years ago

Magdalena Figueroa's covered medical care bills for a recent illness were $8,440.00. Her major medical policy had a coinsurance

devlian [24]

Medical bill = $8,440
Deductible = $400
Coinsurance plan = Medical policy 80% of all expenses above $400

Amount to pay = 400+ (8440-400)*20/100 = 400+1608 = $2,008

8 0

3 years ago

a piece of art is in the shape of an equilateral triangle with side of 6 inches what is the area of the art

Nitella [24]

Area=1/2 times base times height
for equilateral triangle, if base is x, then height is (x√3)/2

so if base is 6 then height is (6√3)/2=3√3

area is 1/2 times 6 times3√3=3 times 3√3=9√3 sqare inches

8 0

3 years ago

Yea uh... mmmmm... may someone help me with this. Thank you so very much! :D

kobusy [5.1K]

What’s the question?

5 0

3 years ago