at a community college a survey was taken to determine where students study on campus. Of the 270 students surveyed, it was determined that 177 studied in the library , 142 studied in the cafeteria, 82 studied in both the library and the cafeteria. Of those students surveyed, how many studied only in the library?

Answer:

1/64

Step-by-step explanation:

25% own a dog, so picking one person has a probability of 1/4 (0.25) for that person to own a dog.

picking 3 people means combining (multiplying) the probabilities of the non-overlapping and non-depending events.

picking the third person has 1/4 chance of owning a dog (as the population is "infinite") combined with the chance that also the second pick owned a dog, which has to be combined with the chance of the first pick owning a dog.

so,

1/4 × 1/4 × 1/4 = 1/4³ = 1/64 = 0.015625

Answer:

a) The error bound of the confidence interval is of 0.66.

b) The confidence interval will be narrower.

Step-by-step explanation:

Question a:

We have to find the margin of error. Considering that we have the standard deviation for the sample, the t-distribution is used.

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

df = 71 - 1 = 70

95% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 70 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 1.9944

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}}[/tex]

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

For this problem, [tex]s = 2.8, n = 71[/tex]. So

[tex]M = T\frac{s}{\sqrt{n}} = 1.9944\frac{2.8}{\sqrt{71}} = 0.66[/tex]

The error bound of the confidence interval is of 0.66.

b. What will happen to the level of confidence obtained if 1,000 male Swedes are surveyed instead of 48? Why?

The margin of error is inversely proportional to the square root of the sample size, so increasing the sample size leads to a smaller margin  of error and a narrower confidence interval.

Answer:

The cotton is $9 per yard and the wool is $11 per yard

Step-by-step explanation:

Create a system of equations where c is the cost per yard for the cotton and w is the cost per yard for the wool.

50c + 80w = 1330

75c + 20w = 895

Solve by elimination by multiplying the bottom equation by -4:

50c + 80w = 1330

-300c - 80w = -3580

Add these together and solve for c:

-250c = -2250

c = 9

Plug in 9 as c into one of the equations, and solve for w:

50c + 80w = 1330

50(9) + 80w = 1330

450 + 80w = 1330

80w = 880

w = 11

The cotton is $9 per yard and the wool is $11 per yard.

Answer:

0.9 = 90% probability that the suspect actually committed the crime.

Step-by-step explanation:

Conditional Probability

We use the conditional probability formula to solve this question. It is

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]

In which

P(B|A) is the probability of event B happening, given that A happened.

[tex]P(A \cap B)[/tex] is the probability of both A and B happening.

P(A) is the probability of A happening.

In this question:

Event A: Charged

Event B: Committed the crime.

16% of crimes of this type end up in a criminal charge.

This means that [tex]P(A) = 0.16[/tex]

Probability of being charged and committing the crime:

90% of 16%, so:

[tex]P(A \cap B) = 0.9*0.16[/tex]

What is the chance that the suspect actually committed the crime?

[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.9*0.16}{0.16} = 0.9[/tex]

0.9 = 90% probability that the suspect actually committed the crime.

Answer:

R = 0.862

Strong positive relationship

Step-by-step explanation:

Given the data:

Test Chemistry Student Score,

x Grade, y

1 2 3 4 5 6 7 8 9 10 11 12

Score,x = 65 50 55 65 55 70 65 70 55 70 50 55

Grade, y = 85 74 76 90 85 87 94 98 81 91 76 74

Using technology :

The CORREL function in excel, calculators will give accurate value of the correlation Coefficient between two variables, x and y. The correlation Coefficient obtained using technology is : 0.862

The correlation Coefficient value ranges between (-1 and 1) with values closer to either - 1 or 1 reflecting stronger relationship. A value of 0 means there is no relationship between the variables. Negative values indicate negative relationships while positive indicates positive association between the variables.

Therefore. With a correlation Coefficient of 0.862, the correlation Coefficient can be interpreted as meaning that ; there is a strong positive relationship between score and grade.

Step-by-step explanation:

yo

so sorry I can't

really answer it

Answer:

4

Step-by-step explanation:

24 = 2^3 x 3

100 = 2^2 x 5^2

HCF = 2^2 = 4

Answer:

For any rectangle, the one with the largest area will be the one whose dimensions are as close to a square as possible.

However, the dividers change the process to find this maximum somewhat.

Letting x represent two sides of the rectangle and the 3 parallel dividers, we have 2x+3x = 5x.

Letting y represent the other two sides of the rectangle, we have 2y.

We know that 2y + 5x = 750.

Solving for y, we first subtract 5x from each side:

2y + 5x - 5x = 750 - 5x

2y = - 5x + 750

Next we divide both sides by 2:

2y/2 = - 5x/2 + 750/2

y = - 2.5x + 375

We know that the area of a rectangle is given by

A = lw, where l is the length and w is the width. In this rectangle, one dimension is x and the other is y, making the area

A = xy

Substituting the expression for y we just found above, we have

A = x (-2.5x+375)

A = - 2.5x² + 375x

This is a quadratic equation, with values a = - 2.5, b = 375 and c = 0.

To find the maximum, we will find the vertex. First we find the axis of symmetry, using the equation

x = - b/2a

x = - 375/2 (-2.5) = - 375/-5 = 75

Substituting this back in place of every x in our area equation, we have

A = - 2.5x² + 375x

A = - 2.5 (75) ² + 375 (75) = - 2.5 (5625) + 28125 = - 14062.5 + 28125 = 14062.5

Step-by-step explanation:

Answer:

31.5

Step-by-step explanation:

Angle Z+ Angle X+ Angle Y=180

As the triangle is isosceles, Z=X, hence Z=63/2=31.5

Let f = ln(x + √(x ² + y ²)) ln(sin(y/x)).

Then the total differential is

[tex]\mathrm df = \dfrac{\mathrm d\left(x+\sqrt{x^2+y^2}\right)}{x+\sqrt{x^2+y^2}}\ln\left(\sin\left(\dfrac yx\right)\right) + \ln\left(x+\sqrt{x^2+y^2}\right)\dfrac{\mathrm d\left(\sin\left(\frac yx\right)\right)}{\sin\left(\frac yx\right)}[/tex]

[tex]\mathrm df = \dfrac{\mathrm dx + \frac{\mathrm d(x^2+y^2)}{\sqrt{x^2+y^2}}}{x+\sqrt{x^2+y^2}}\ln\left(\sin\left(\dfrac yx\right)\right) + \ln\left(x+\sqrt{x^2+y^2}\right)\dfrac{\cos\left(\frac yx\right)\,\mathrm d\left(\frac yx\right)}{\sin\left(\frac yx\right)}[/tex]

[tex]\mathrm df = \dfrac{\mathrm dx + \frac{2x\,\mathrm dx+2y\,\mathrm dy}{\sqrt{x^2+y^2}}}{x+\sqrt{x^2+y^2}\right)\ln\left(\sin\left(\dfrac yx\right)\right) + \ln\left(x+\sqrt{x^2+y^2}}\right)\dfrac{\cos\left(\frac yx\right)\frac{x\,\mathrm dy-y\,\mathrm dx}{x^2}}{\sin\left(\frac yx\right)}[/tex]

[tex]\mathrm df = \dfrac{\left(2x+\sqrt{x^2+y^2}\right)\,\mathrm dx +2y\,\mathrm dy}{x\sqrt{x^2+y^2}+x^2+y^2\right)\ln\left(\sin\left(\dfrac yx\right)\right) \\\\ \indent + \dfrac1{x^2}\cot\left(\dfrac yx\right)\ln\left(x+\sqrt{x^2+y^2}}\right)(x\,\mathrm dy-y\,\mathrm dx)[/tex]

[tex]\mathrm df = \left(\left(\dfrac{2x+\sqrt{x^2+y^2}}{x\sqrt{x^2+y^2}+x^2+y^2}\right)\ln\left(\sin\left(\dfrac yx\right)\right) - \dfrac y{x^2}\cot\left(\dfrac yx\right)\ln\left(x+\sqrt{x^2+y^2}\right)\right)\,\mathrm dx \\\\ \indent + \left(\dfrac{2y}{x\sqrt{x^2+y^2}+x^2+y^2}\ln\left(\sin\left(\dfrac yx\right)\right)+\dfrac1x\cot\left(\dfrac yx\right)\ln\left(x+\sqrt{x^2+y^2}\right)\right)\,\mathrm dy[/tex]

The ratio/proportion is young / old = young / old.

We know that one ratio is 3 / 5, so we need to complete the other.

3 / 5 = young / 40

5 goes into 40, 8 times, therefore we need to multiply the numerator by 8 also.

3 x 8 = 24

The younger student is 24 years old.

Hope this helps!

Answer:

24

Step-by-step explanation:

younger : older

3             :5

The older is 40

40/5 = 8

Multiply each by 8

younger : older

3 *8       :5 *8

24         : 40

The younger is 24

Answer:

a

Step-by-step explanation:

Answer:

An online poll is created for sports fans to vote on the winner for the Super Bowl.

Each employee is given a mandatory survey to complete about health benefits.

A used car dealer surveys potential customers about the type of car they are interested in so he can plan his future inventory.

2,3,6 : B,C,F

ED2021

9514 1404 393

Answer:

  A.  96

Step-by-step explanation:

The surface area is the sum of the areas of the two triangular bases and the areas of the three rectangular lateral faces.

  A = 2(1/2)bh + PH

where b is the base of the triangle, h is its height, P is the perimeter of the triangle, and H is the height of the prism.

  A = (3 cm)(4 cm) +(3 +4 +5 cm)(7 cm) = 12 cm² +84 cm²

  A = 96 cm²

The surface area of the triangular prism is 96 square cm.

The length of the confidence interval is the margin of error, which is the ratio of the standard deviation and the square root of sample size. Hence, to reduce the length of confidence interval by half, Quadruple the sample size.

Recall :

Evaluating an hypothetical scenario :

Let standard deviation, σ = 2

Sample size = 50

Margin of Error = 2/√50 = 0.554

Using Quadruple of the sample size : (50 × 4) = 200 samples

(0.227 ÷ 0.554) = 0.5

Therefore, increasing the sample size, reduces the margin of error. Hence, using quadruple the sample size, will reduce the margin of error by half.

Learn more : https://brainly.com/question/13403969

Answer:

x = 42

Step-by-step explanation:

24+8 = 32

[tex]\frac{x}{24}[/tex] = [tex]\frac{x+14}{32}[/tex]

32x = 24(x+14)

32x = 24x+336

8x = 336

x = 42

a=2,5937

b=2,7048

c=2,7181

d=2,7183

e=2,7183

Answer:

(a)

Number of cars with defective turn signals = 65

Number of cars with no defective turn signals = 410 - 65 = 345

Required probability:

(b)

Number of cars with defects = 65 + 35 = 100

Number of cars with no defects = 410 - 100 = 310

Required probability:

Answer:

((c)).g(x) = 3 × 2^x +2..

Answer:

5years, 3months, 16 days

We know

Sum of two interior angles=exterior angle

[tex]\\ \sf\longmapsto 20°+120°=<y[/tex]

[tex]\\ \sf\longmapsto <y=20°+120°[/tex]

[tex]\\ \sf\longmapsto <y=140°[/tex]

Hope it helps

Answer:

0.7734 = 77.34% probability that at least 22 will contain an error. Probability above 50%, which means that this is likely to occur.

Step-by-step explanation:

Binomial probability distribution

Probability of exactly x successes on n repeated trials, with p probability.

Can be approximated to a normal distribution, using the expected value and the standard deviation.

The expected value of the binomial distribution is:

[tex]E(X) = np[/tex]

The standard deviation of the binomial distribution is:

[tex]\sqrt{V(X)} = \sqrt{np(1-p)}[/tex]

Normal probability distribution

Problems of normally distributed 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.

When we are approximating a binomial distribution to a normal one, we have that [tex]\mu = E(X)[/tex], [tex]\sigma = \sqrt{V(X)}[/tex].

About 12.5% of restaurant bills are incorrect.

This means that [tex]p = 0.125[/tex]

200 bills are selected at random

This means that [tex]n = 200[/tex]

Mean and standard deviation:

[tex]\mu = E(X) = np = 200*0.125 = 25[/tex]

[tex]\sigma = \sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{200*0.125*0.875} = 4.677[/tex]

Find the probability that at least 22 will contain an error.

Using continuity correction, this is [tex]P(X \geq 22 - 0.5) = P(X \geq 21.5)[/tex], which is 1 subtracted by the p-value of Z when X = 21.5. So

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

[tex]Z = \frac{21.5 - 25}{4.677}[/tex]

[tex]Z = -0.75[/tex]

[tex]Z = -0.75[/tex] has a p-value of 0.2266.

1 - 0.2266 = 0.7734

0.7734 = 77.34% probability that at least 22 will contain an error. Probability above 50%, which means that this is likely to occur.

Answer : 19.6cm

I hope this helps you! Have a good day!

Answer:

24 men will take 3 days to dig a 72 meter trench.

Step-by-step explanation:

If 16 workers dig an 80-meter long trench in five days, how long will it take 24 workers to dig a 72-meter long trench?

If 16 workers take 5 days to dig an 80 meter long trench,

24 workers will definitely take lesser time to dig a 72 meter long trench as both the length of the trench and the number of workers is more

Lets write these values down in order: Number of Workers, Length of Trench, Number of Days:

16 80 5

24 72 ?

Lets represent the ? as x:

We know that Ratio of Trench length to men = 80/16 : 72/24 or 5 : 3

Which means that the first set (16 men) will take 5 days to dig a trench of 80 meters.

And therefore from the above ratio (5: 3), 24 men will take 3 days to dig a 72 meter trench.

HOPE IT WILL DEFINITELY HELP YOU

Answer:

Step-by-step explanation:

Semicircle:

Shaded area of semicircle = area of outer semicircle - area of inner semicircle

Outer semicircle:

d = 40 m  r = 40/2 = 20m

Area of outer semicircle = πr²

                                        = 3.14*20*20

                                        =    1256 m²

Inner semicircle:

d = 30 m  r = 30/2 = 15 m

Area of outer semicircle = πr²

                                        = 3.14*15*15

                                        =  706.5 m²

Shaded area of semicircle = 1256 - 706.5 = 549.5 m²

Shaded area of semicircle in both sides = 2 * 549.5 = 1099 m²

Rectangle on both sides:

Length = 50 m

width = 30 m

Area of shaded rectangles on both sides = 2* (length *width)

                                                                      = 2* 50 * 30

                                                                       = 3000 m²

Shaded area = 1099 + 3000 = 4099 m²