QUICK HELP with the Image below

Answer:

a) A sample of 385 must be taken.

b) The 95% confidence interval for the proportion of workers who have changed jobs within the past year is (0.1216, 0.2784).

c) A sample of 246 is needed.

Step-by-step explanation:

Question a:

In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].

The margin of error is:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

Absence of preliminary data:

This means that we use [tex]\pi = 0.5[/tex], which is when the largest sample will be needed.

95% confidence level

So [tex]\alpha = 0.05[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].

How large a sample must be taken to ensure that a 95% confidence interval will specify the proportion to within ±0.05?

A sample of n must be taken.

n is found when [tex]M = 0.05[/tex]. So

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]0.05 = 1.96\sqrt{\frac{0.5*0.5}{n}}[/tex]

[tex]0.05\sqrt{n} = 1.96*0.5[/tex]

Dividing both sides by 0.05

[tex]\sqrt{n} = 1.96*10[/tex]

[tex](\sqrt{n})^2 = (19.6)^2[/tex]

[tex]n = 384.16[/tex]

Rounding up,

A sample of 385 must be taken.

Question b:

In a sample of 100 workers, 20 of them had changed jobs within the past year.

This means that [tex]n = 100, \pi = \frac{20}{100} = 0.2[/tex]

The lower limit of this interval is:

[tex]\pi - z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.2 - 1.96\sqrt{\frac{0.2*0.8}{100}} = 0.1216[/tex]

The upper limit of this interval is:

[tex]\pi + z\sqrt{\frac{\pi(1-\pi)}{n}} = 0.2 + 1.96\sqrt{\frac{0.2*0.8}{100}} = 0.2784[/tex]

The 95% confidence interval for the proportion of workers who have changed jobs within the past year is (0.1216, 0.2784).

Question c:

Same procedure as question a, just with [tex]\pi = 0.2[/tex]

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]0.05 = 1.96\sqrt{\frac{0.2*0.8}{n}}[/tex]

[tex]0.05\sqrt{n} = 1.96\sqrt{0.2*0.8}[/tex]

[tex]\sqrt{n} = \frac{1.96\sqrt{0.2*0.8}}{0.05}[/tex]

[tex](\sqrt{n})^2 = (\frac{1.96\sqrt{0.2*0.8}}{0.05})^2[/tex]

[tex]n = 245.8[/tex]

Rounding up

A sample of 246 is needed.

Step-by-step explanation:

Supplementary angles add up to 180

Complementary angles add up to 90

you can check those angles by adding them up

121+59=180                 Supplementary

49+51=100                  Neither

25+65=90                  Complementary

Hope that helps :)

Step-by-step explanation:

answer:

i believe 28

Step-by-step explanation:

Answer:

65

Step-by-step explanation:

Hi,

Triangles will always add up to 180 degrees. So, 62 + 53 = 115. Subtract it from 180, 180 - 115, and you get 65.

I hope this helps :)

Answer:

65

Step-by-step explanation:

The sum of the three angles of any triangle is equal to 180 degrees

Answer:

the lines are perpendicular because they have the same slope so the correct answer would be c

Step-by-step explanation:

Answer:

B

Step-by-step explanation:

Answer:

Answer: 135/pi

Step-by-step explanation: Circumference is 16pi. So then 6/16pi is the fraction of the 360 arc measure of the entire circle that is the angle measure of the arc, so we multiply 6/16pi times 360 and yield 135/pi. Hope this helps!

Answer:

0.0035 = 0.35% probability that the mean amplifier output would be greater than 432.1 watts.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

Mean output of 429 watts with a standard deviation of 10 watts.

This means that [tex]\mu = 429, \sigma = 10[/tex]

Sample of 76:

This means that [tex]n = 76, s = \frac{10}{\sqrt{76}} = 1.147[/tex]

What is the probability that the mean amplifier output would be greater than 432.1 watts?

This is 1 subtracted by the pvalue of Z when X = 432.1. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{432.1 - 429}{1.147}[/tex]

[tex]Z = 2.7[/tex]

[tex]Z = 2.7[/tex] has a pvalue of 0.9965

1 - 0.9965 = 0.0035

0.0035 = 0.35% probability that the mean amplifier output would be greater than 432.1 watts.

Answer:

Equation: 4.8 times 5.2 then divided by 2

= 12.48 (area)

Step-by-step explanation:

The formula of finding the area of a triangle:

base * height then divided by 2

* = multiply

Base: 4.8

Height: 5.2

multiply them

= 24.96

then divide by 2

= 12.48

hope this helped :)

Answer:

12.48

Step-by-step explanation:

5.2 times 4.8 is is 24.96 and that divded by 2 is 12.48

Answer:

New price is $12.75

New attendance is 57500

Step-by-step explanation:

For starters, we use the relation.

18 - 3x

Since we don't know the number of times we're expected to deduct $3 from the price.

Again, we have 40000 + 10000x on another hand. Question says to add 10000 people everytime $3 is deducted.

Since (40000 + 10000x) is the number of people, we multiply it by $4.50, the average amount each person spends is then gotten to be

(18 - 3x) (40000 + 10000x) + (40000 + 10000x) (4.5) = 0

Expanding the bracket, we have

[720000 + 60000x - 30000x²] + [180000 + 45000x] = 0, solving further, we have

900000 + 105000x - 30000x² = 0 or

-30000x² + 105000x + 900000 = 0

Then, we find the maximum of a quadratic, by finding the axis of symmetry. Use x = -b/2a

x = -105000 / 2 * -30000

x = -105000 / -60000

x = 1.75

From our earlier equations, the new price then is

18 - 3(1.75) = 18 - 5.25 = $12.75

The new attendance also is

40000 + 10000(1.75) =

40000 + 17500 = 57500

Answer:

a) a = 12s

Step-by-step explaination:

Answer:

4

Step-by-step explanation:

The pre-image is the starting coordinates and it then gets larger. when you multiply four by 3 you get 12 and when you multiply four by -4 you get 16. So the pre-image dilated by 4.

Answer:

Here is the work I did yesterday for you

Step-by-step explanation:

Answer: 4 months

Look at it this way: 6 books in a group. How many groups are there? well this is multiplication. Just add 6 a bunch of times until you get 24. You will add 6+6+6+6. There are 4 6's. This means, there are 4 months, with 6 books each month.

Answer: 4months

Step-by-step explanation:

Consider this: a set of six novels. What is the total number of groups? This is, after all, multiplication. Simply multiply 6 by 6 until you have 24. You'll multiply 6 by 6 by 6 by 6 There are four sixes. This implies there are four months in all, each with six books.

Answer:

y=8 i think

Step-by-step explanation:

Answer: y=8

Step-by-step explanation: You divide 18y/18 to isolate y but what you do to one side you must do to the other do you divide 144/18 as well so get the answer of y=8

I hope this helps you or anybody!

Answer:

x=9

y=20

Step-by-step explanation:

6/8=3/4

x/12=9/12=3/4

15/y=15/20=3/4

there's your answer.............

Answer:

uhh 7 maybe?

Step-by-step explanation:

i dont know

Answer:

m = -3/4

Step-by-step explanation:

-5 - 1 / 6 - -2 = -6/8 = -3/4

Answer:

Step-by-step explanation:

(-5 - 1)/(6 + 2)= -6/8 = -3/4

Answer:

(6*y130896+1%315£&+)

(19+!re

<4=22°

Answer:

<4+158=180 co interior angle

<4=180-158=22°

Answer:

solution given:

<4+<158°=180°[co- interior angle]

<4=180°-<158°=22°

<4=22° is your answer

Answer:

3/5

Step-by-step explanation:

5/5 - 2/5 = 3/5

Answer:

5/12 cup of water per plant

Answer:

acute, equilateral

Step-by-step explanation:

Answer:

Acute, equilateral

Step-by-step explanation:

Angle of 60 is acute and it is an equilateral triangle.

Answer:

The airline should expect a revenue of $1,884 for a flight of 120 passengers

Step-by-step explanation:

For each passenger:

54% of passengers have no checked luggage, that is, 54% probability of no revenue.

34% have one piece, that is, 34% probability of $25 revenue.

12% have two pieces, that is, 12% probability of $60 revenue.

The expected revenue for a single passenger is:

[tex]E = 0.54*0 + 0.34*25 + 0.12*60 = 15.7[/tex]

For 120 passengers

15.7*120 = $1,884

The airline should expect a revenue of $1,884 for a flight of 120 passengers