The management of a large airline wants to estimate the average time after takeoff taken before the crew begins serving snacks and beverages on their flights. Assuming that management has easy access to all of the information that would be required to select flights by each proposed method, which of the following would be reasonable methods of stratified sampling?

a. For each day of the week, randomly select 5% of all flights that depart on that day of the week.
b. Divide all flights into the following 4 groups on the basis of scheduled departure time: before 9:00 am 9:00 am to 1:00 pm. 1:00 pm to 5:00 pm, and after 5:00 pm. Randomly select 5% of the flights in each group.
c. For each crew member the airline employs, randomly select 5 flights that the crew member works.
d. Divide the airports from which the airline's fights depart into 4 regions: Northeast, Northwest Southwest and Southeast. Randomly select 5% of all flights departing from airports in each region

Answer:

y = 2x - 5

Step-by-step explanation:

[tex]y+3=2(x-1)\\y+3=2x-2\\y+3-3=2x-2-3\\y=2x-5[/tex]

Answer:

y=0.5

Step-by-step explanation:

14y-6(y-3)=22

14y-6y+18=22

8y+18=22

8y=4

y=0.5

Then we check our work...

14(0.5)-6((0.5)-3)=22

7-6(-2.5)=22

7+15=22

7+15 does equal 22, so this solution is correct.

Answer:

A. 1 + 3x = -89

B. x = -30

Step-by-step explanation:

Let the unknown variable be x.

A. Translating the word problem into an algebraic expression, we have;

1 + 3x = -89

B. To solve for the unknown variable;

1 + 3x = -89

3x = -89 -1

3x = -90

x = -90/3

x = -30

Check:

1 + 3x = -89

Substituting the value of x;

1 + 3(-30) = -89

1 + (-90) = -89

1 - 90 = -89

-89 = -89

Answer:

We Reject the Null, H0 and conclude that the volume of juice filled by old machine varies more than volume filled by new machine

Step-by-step explanation:

Given the data:

Old machine: 8.2, 8.0, 7.9, 7.9, 8.5, 7.9, 8.1,8.1, 8.2, 7.9

Sample size, n = 10

Using calculator :

s1² = 0.37889.

New machine: 8.0, 8.1, 8.0, 8.1, 7.9, 8.0, 7.9, 8.0, 8.1

Sample size, n = 9

s2² = 0.006111

Hypothesis :

H0 : s1² = s2²

H1 : s1² > s2²

New machine :

s2² = 0.006111 ; n = 9

Using the Ftest :

Ftest statistic = larger sample variance / smaller sample variance

Ftest statistic = 0.37889 / 0.006111

Ftest statistic = 62.0

Decision region :

Reject H0 ; If Test statistic > Critical value

The FCritical value at 0.05

DFnumerator = 10 - 1 = 9

DFdenominator = 9 - 1 = 8

Fcritical(0.05, 9, 8) = 3.388

Since 62 > 3.388 ; Reject H0 and conclude that volume filled by old machine varies more than volume filled by new machine

Answer:

y = d + a · cos(bx - c) ⇒ y = -4cos(4/3x)

Amplitude = |a| = |-4| = 4

Period = [tex]\frac{2\pi }{b} =\frac{2\pi }{\frac{4}{3} } =2\pi *\frac{3}{4} =\frac{3}{2} \pi[/tex]

Answer:

The milk cost $2.10 each the snacks cost $1.535 each the water cost $3.07 each

Step-by-step explanation:

I think Im right

Answer:

a. mg/c b. 4. It is the speed the object approaches as time goes on.

Step-by-step explanation:

a. Calculate lim v  as t→[infinity]

Since v = mg/c(1 - e^ -ct/m)

[tex]\lim_{t \to \infty} v = \lim_{t \to \infty} (\frac{mg}{c}[1 - e^{-\frac{ct}{m} } ] )[/tex]

[tex]\lim_{t \to \infty} v =[/tex] mg/c(1 - e^(-c(∞)/m))

[tex]\lim_{t \to \infty} v =[/tex] mg/c(1 - e^(-∞/m))

[tex]\lim_{t \to \infty} v =[/tex] mg/c(1 - e^(-∞))

[tex]\lim_{t \to \infty} v =[/tex] mg/c(1 - 0)

[tex]\lim_{t \to \infty} v =[/tex] mg/c(1)

[tex]\lim_{t \to \infty} v =[/tex] mg/c

b. What is the meaning of this limit?

4. It is the speed the object approaches as time goes on.

This is because, since t → ∞ implies a long time after t = 0, the limit of v as t → ∞ implies the speed of the object after a long time. So, the limit of v as t → ∞ is the speed the object approaches as time goes on.

Answer:5

Step-by-step explanation:

Where the above parameters are given,  you need to walk a distance of approximately √41 miles back to your car.

To calculate the total distance you need to walk, you can use the Pythagorean theorem since you have a right triangle formed by the north and east displacements.

Distance = √((Distance north)² + (Distance east)²)

= √((5 miles)² + (4 miles)²)

= √(25 miles + 16 miles)

= √41 miles

Hence, you need to walk a distance of  approximately √41 miles back to your car.

As for the direction, based on the net displacements, you are 5 miles north and 4 miles east of your car, so the direction would be a combination of north and east, often referred to as northeast.

Learn more about distance  at:

https://brainly.com/question/26046491

#SPJ2

Answer:

a) 0.9544 = 95.44% of scores lie between 220 and 380 points.

b) 0.1587 = 15.87% probability that a randomly chosen student scores is below 260.

c) 25.14% of scores are above 326.8 points.

Step-by-step explanation:

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.

Mean of 300 and a standard deviation of 40.

This means that [tex]\mu = 300, \sigma = 40[/tex]

(a) What proportion of scores lie between 220 and 380 points?

This is the p-value of Z when X = 380 subtracted by the p-value of Z when X = 220.

X = 380

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

[tex]Z = \frac{380 - 300}{40}[/tex]

[tex]Z = 2[/tex]

[tex]Z = 2[/tex] has a p-value of 0.9772.

X = 220

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

[tex]Z = \frac{220 - 300}{40}[/tex]

[tex]Z = -2[/tex]

[tex]Z = -2[/tex] has a p-value of 0.0228.

0.9772 - 0.0228 = 0.9544

0.9544 = 95.44% of scores lie between 220 and 380 points.

(b) What is the probability that a randomly chosen student scores is below 260?

This is the p-value of Z when X = 260. So

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

[tex]Z = \frac{260 - 300}{40}[/tex]

[tex]Z = -1[/tex]

[tex]Z = -1[/tex] has a p-value of 0.1587.

0.1587 = 15.87% probability that a randomly chosen student scores is below 260.

(c) What percent of scores are above 326.8 points?

The proportion is 1 subtracted by the p-value of Z when X = 326.8. So

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

[tex]Z = \frac{326.8 - 300}{40}[/tex]

[tex]Z = 0.67[/tex]

[tex]Z = 0.67[/tex] has a p-value of 0.7486.

1 - 0.7486 = 0.2514

0.2514*100% = 25.14%

25.14% of scores are above 326.8 points.

Answer:

Hence, MEAN OF FIRST FIVE COMPOSITE NOS IS 7.5

Answer:

2k-3

Step-by-step explanation:

the square of k is k times k so 2k (two times k) and less than three means minus three.

Answer:

The 95% confidence interval for the mean time for all players, in minutes, is: (7.95, 11.01).

Step-by-step explanation:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

The first step to solve this problem is finding how many degrees of freedom,which is the sample size subtracted by 1. So

df = 10 - 1 = 9

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 9 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 2.2622.

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 2.2622\frac{2.14}{\sqrt{10}} = 1.53[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 9.48 - 1.53 = 7.95 minutes.

The upper end of the interval is the sample mean added to M. So it is 9.48 + 1.53 = 11.01 minutes.

The 95% confidence interval for the mean time for all players, in minutes, is: (7.95, 11.01).

Answer:

We have 60% salt and 85% salt solutions and we need 140 ounces of a solution that is 80% salt.

We set up 2 equations:

A) x + y = 140

B) .60x + .85y = .80 * 140

Multiply equation A) by -.60

A) -.60x -.60y = -84  then we add this to B)

B) .60x + .85y = 112

.25y = 28

y = 112 ounces of 85% salt

x = 28 ounces of 60% salt.

Double Check

112 * .85 = 95.2 AND 28 * .60 = 16.80

95.2 + 16.80 = 112

and 112/140 = 80 per cent!!

Source: http://www.1728.org/mixture.htm

Step-by-step explanation:

Answer:

-7.5

Alternatively,

-0.5(units^-1) + (-4(units^0)) + (-3(units))

Step-by-step explanation:

On graph, only clearly defined points:

1. x = -3 , y = 0

2. x = -3 , y = -8

3. x = 5 , y = -4

So for:

1. -3 = c ( + a×(0^2) + b×0)

And

2. -3 = a×((-8)^2) + b×(-8) + c = 64×a + (-8)×b + c

Since c = -3 ==> 64×a - 8×b = 0

Simplified ==> 8×a - b = 0 ==> b = 8×a

3. 5 = a×((-4)^2) + b×(-4) + c = 16×a + (-4)×b + c

Since c = -3 ==> 16×a - 4×b = 5 - (-3) = 8

Simplified ==> 4×a - b = 2

Since b = 8×a ==> 4×a - (8×a) = 2

Simplified ==> 2×a - 4×a = 1

==> -2×a = 1

==> a = -0.5

Since b = 8×a ==> b = 8×(-0.5) = -4

So...

c = -3

b = -4

a = -0.5

Then...

a + b + c = -0.5 - 4 - 3 = -7.5

Answer:

6 hours.

Step-by-step explanation:

x = supervisor's hours alone

Since there are two people working together, you need to incorporate some kind of 2 in this problem.

If the postal worker was cloned, it would take 4 hours.

3 x 2 = 6.

Answer:

184.8

Step-by-step explanation:

y =kx

k=y/x

k=42/5=8.4

y=8.4*22

9514 1404 393

Answer:

  the red angle has no specific value

Step-by-step explanation:

There is sufficient information here to specify all of the angles except the two unknown angles in the 70° (dark blue) triangle. Those two angles must total 110°, but that measure cannot be allocated between them based on the information in the diagram.

The attachments show that all of the given angle constraints can be met while the red angle may vary considerably. It can range through the interval (0°, 110°), but cannot be either of those end values.

Base case (n = 1):

• left side = 1×2² = 4

• right side = 1×(1 + 1)×(3×1² + 11×1 + 10)/12 = 4

Induction hypothesis: Assume equality holds for n = k, so that

1×2² + 2×3² + 3×4² + … + k × (k + 1)² = k × (k + 1) × (3k ² + 11k + 10)/12

Induction step (n = k + 1):

1×2² + 2×3² + 3×4² + … + k × (k + 1)² + (k + 1) × (k + 2)²

= k × (k + 1) × (3k ² + 11k + 10)/12 + (k + 1) × (k + 2)²

= (k + 1)/12 × (k × (3k ² + 11k + 10) + 12 × (k + 2)²)

= (k + 1)/12 × ((3k ³ + 11k ² + 10k) + 12 × (k ² + 4k + 4))

= (k + 1)/12 × (3k ³ + 23k ² + 58k + 48)

= (k + 1)/12 × (3k ³ + 23k ² + 58k + 48)

On the right side, we want to end up with

(k + 1) × (k + 2) × (3 (k + 1) ² + 11 (k + 1) + 10)/12

which suggests that k + 2 should be factor of the cubic. Indeed, we have

3k ³ + 23k ² + 58k + 48 = (k + 2) (3k ² + 17k + 24)

and we can rewrite the remaining quadratic as

3k ² + 17k + 24 = 3 (k + 1)² + 11 (k + 1) + 10

so we would arrive at the desired conclusion.

To see how the above rewriting is possible, we want to find coefficients a, b, and c such that

3k ² + 17k + 24 = a (k + 1)² + b (k + 1) + c

Expand the right side and collect like powers of k :

3k ² + 17k + 24 = ak ² + (2a + b) k + a + b + c

==>   a = 3   and   2a + b = 17   and   a + b + c = 24

==>   a = 3, b = 11, c = 10

Answer:

[tex]15y^9 - 7y^3 + y[/tex]

Nonic polynomial

Step-by-step explanation:

Given

[tex]y - 7y^3 + 15y^9[/tex]

Required

Write in standard form

The standard form of a polynomial is:

[tex]ay^n + by^{n-1} + ......... + k[/tex]

So, we have:

[tex]y - 7y^3 + 15y^9[/tex]

The standard form is:

[tex]15y^9 - 7y^3 + y[/tex]

And the name is: Nonic polynomial (because it has a degree of 9)

Answer:

84°

Step-by-step explanation:

the total angle in a straight line sum up to 180°

Answer: [tex]y=\frac{1}{3}x+\frac{13}{3}[/tex]

Step-by-step explanation:

(slope = m)

[tex]m=\frac{y_2-y_1}{x_2-x_1}=\frac{4-6}{-1-5}=\frac{-2}{-6}=\frac{1}{3}[/tex]

[tex]y=mx+b, (5,6), (-1,4), m=\frac{1}{3}[/tex]

[tex]y=mx+b\\6=\frac{1}{3}(5)+b\\b=6-\frac{5}{3} \\b=\frac{13}{3}\\y=\frac{1}{3}x+\frac{13}{3}[/tex]

Answer:

CI ≈ (173.8 < μ < 196.2)

Step-by-step explanation:

We are told that laboratory tested twelve chicken eggs. Thus;

n = 12

Mean; x¯ = 185 mg

S.D; s = 17.6 mg

DF = n - 1 = 12 - 1 = 11

We have a 95% confidence level. Thus; α = 0.05

Since n < 30, we will use t-sample test.

Thus, from t-table attached at 95% Confidence level and DF = 11, we have;

t = 2.201

Thus,formula for Confidence interval is;

CI = (x¯ - t(s/√n)) < μ < (x¯ + t(s/√n))

CI = (185 - 2.201(17.6/√12)) < μ < (185 + 2.201(17.6/√12))

CI = (185 - 11.1825) < μ < (185 + 11.1825)

CI = (173.8175 < μ < 196.1825)

CI ≈ (173.8 < μ < 196.2)

Answer:

speaking giberish

Step-by-step explanation:

cos it is just a word that is rare

Answer:

f(x) can not be equal to g(x)

Step-by-step explanation:

If the result is possible:

f(x) = g(x)

x + 8 = x + 2

x + 8 - (x + 2) = x + 2 - (x + 2)

6 = 0

Because 6 can't be equal to 0, so do f(x) can't be equal to g(x)

Answer:

y=-1/2x+-1

Step-by-step explanation:

try desmos with this equation.

y=mx+b

m=the slope which is -1/2. It goes down 1 it is negative because it is going down, and to the right 2.

b=y-intercept meaning the point which the line crosses the line y .-1

Answer:

$3.55

Step-by-step explanation:

1st number after 0 is tenths, 2nd is hundredths.

since the number after is 5, we round up

Answer:

no solution

Step-by-step explanation:

a negative number cannot be square rooted

Answer:

"not possible". no such thing as a negative squared number