Random samples of size 17 are taken from a population that has 200 elements, a mean of 36, and a standard deviation of 8. The mean and the standard deviation of the sampling distribution of the sample means are:___________.
A) 8.7 and 1.94
B) 36 and 1.94
C) 36 and 1.86

Answer:

[tex]n=\frac{0.5(1-0.5)}{(\frac{0.03}{1.96})^2}=1067.11[/tex]  

And rounded up we have that n=1068

Step-by-step explanation:

For this case we have the following info given:

[tex] ME=0.03[/tex] the margin of error desired

[tex]Conf= 0.95[/tex] the level of confidence given

The margin of error for the proportion interval is given by this formula:  

[tex] ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}[/tex]    (a)  

the critical value for 95% of confidence is [tex] z=1.96[/tex]

We can use as estimator for the population of interest [tex]\hat p=0.5[/tex]. And on this case we have that [tex]ME =\pm 0.03[/tex] and we are interested in order to find the value of n, if we solve n from equation (a) we got:  

[tex]n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}[/tex]   (b)  

And replacing into equation (b) the values from part a we got:

[tex]n=\frac{0.5(1-0.5)}{(\frac{0.03}{1.96})^2}=1067.11[/tex]  

And rounded up we have that n=1068

Answer:

Step-by-step explanation:

x + y = 15

11x + 9y = 156

Answer:

See Attachment

Step-by-step explanation:

I have attached the geometric diagram of the scenario below.

parallel lines = lines t and u, transversal line = line v, the angles which t makes with v are 1 and a, the angles which u makes with v are b and 2.

Answer:

For x

We use cosine

cos 45° = 2/x

After solving

x = 2√2

Since we have the value of x we use it to get the value of y

we use cosine

cos 60° = 2√2/y

y =2√2/cos 60

y = 4√2

We use Pythagoras theorem to find z

(4√2)² = (2√2)² + z²

z² = 32 - 8

z² = 24

z = √24

z = 2√6

Therefore x = 2√2

y = 4√2

z = 2√6

Hope this helps.

Answer:

The number which is exactly in between 1/3 and 7/8 will be their average. The average = (1/3 + 7/8) / 2 = (8/24 + 21/24) / 2 = (29/24) / 2 = 29/48.

Answer:

The height of the flagpole = 4.50m (3signifiant figures)

Question:

A tree and a flagpole are on the same

horizontal ground. A bird on top of the

tree observes the top and bottom of the flagpole below it at angles of 45° and 60° respectively. If the tree is 10.65 m high, Calculate Correct to 3 significant figures the height of the flagpole.

Step-by-step explanation:

First we have to represent the above information with a diagram to enable us solve the question.

Then label them for easy identification.

To determine the distance between the tree and flagpole, we would apply tangent rule.

Let their distance = x

Tan60 = opposite/adjacent

Tan60 = 10.65/y

Tan60 × y = 10.65

y = 10.65/Tan60

y = 10.65/1.7321

y = 6.15m

See attachment for the concluding part

Answer:

Number of orders seen on last Tuesday = 605

Step-by-step explanation:

Number of orders seen on Tuesday = 600

It is given that it is 0.85% less than last Tuesday.

Let number of sales on last Tuesday = [tex]x[/tex]

As per question statement:

Number of order on last Tuesday - 0.85% of Number of order on last Tuesday = 600

OR

i.e. if we subtract 0.85% of x from x, it must be equal to 600.

[tex]x-\dfrac{0.85}{100}x =600\\\Rightarrow x-\dfrac{0.85}{100}x =600\\\Rightarrow \dfrac{100-0.85}{100}x =600\\\Rightarrow \dfrac{99.15}{100} \times x =600\\\Rightarrow x =\dfrac{600\times 100}{99.15}\\\Rightarrow x =\dfrac{60000}{99.15}\\\Rightarrow x \approx 605[/tex]

So, there were about 605 order seen last Tuesday.

Answer:

The numbers are 2 and 8.

Solution,

Let the numbers be X and 4x

[tex] \frac{1}{x} + \frac{1}{4x} = \frac{5}{8} \\ or \: \frac{1 \times 4 + 1}{4x} = \frac{5}{8} \\ or \: \frac{4 + 1}{4x} = \frac{5}{8} \\ or \: \frac{5}{4x} = \frac{5}{8} \\ or \: 5 \times 4x = 5 \times 8(cross \: multiplication) \\ or \: 20x = 40 \\ or \: x = \frac{40}{20} \\ x = 2 \\ again \\ 4x \\ = 4 \times x \\ = 4 \times 2 \\ = 8[/tex]

hope this helps...

Good luck on your assignment..

Answer:

[tex]12[/tex]

Step-by-step explanation:

[tex]\frac{60}{4+1}[/tex]

[tex]\frac{60}{5} =12[/tex]

[tex]4:1[/tex]

[tex]4 \times 12: 1 \times 12[/tex]

[tex]48:12[/tex]

Answer:

1/3

Step-by-step explanation:

hello,

probability of 1 = 1/6

probability of 2 = 1/6

probability of 1 or 2 = 1/6+1/6 as probability of 1 and 2 = 0

so the answer is 2/6=1/3

Answer:

a) 6.68% of heights less than 150 centimeters

b) 58.65% of heights between 160 centimeters and 180 centimeters

Step-by-step explanation:

When the distribution is normal, we use the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.

In this question, we have that:

[tex]\mu = 162, \sigma = 8[/tex]

a) The percentage of heights less than 150 centimeters

We have to find the pvalue of Z when X = 150. So

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

[tex]Z = \frac{150 - 162}{8}[/tex]

[tex]Z = -1.5[/tex]

[tex]Z = -1.5[/tex] has a pvalue of 0.0668

6.68% of heights less than 150 centimeters

b) The percentage of heights between 160 centimeters and 180 centimeters

We have to find the pvalue of Z when X = 180 subtracted by the pvalue of Z when X = 160.

X = 180

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

[tex]Z = \frac{180 - 162}{8}[/tex]

[tex]Z = 2.25[/tex]

[tex]Z = 2.25[/tex] has a pvalue of 0.9878

X = 160

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

[tex]Z = \frac{160 - 162}{8}[/tex]

[tex]Z = -0.25[/tex]

[tex]Z = -0.25[/tex] has a pvalue of 0.4013

0.9878 - 0.4013 = 0.5865

58.65% of heights between 160 centimeters and 180 centimeters

Answer:

y = 5x

Step-by-step explanation:

First, find the slope of the first equation by doing rise/run

This gets you -10/-2 or 5

A parallel line will have the same slope. Since it goes through the origin, the y-intercept and b value will be zero

The equation will be y = 5x

Answer:

0.006% probability that the final vote count is unanimous.

Step-by-step explanation:

For each person, there are only two possible outcomes. Either they vote yes, or they vote no. The probability of a person voting yes or no is independent of any other person. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

Random voting:

So 50% of voting yes, 50% no, so [tex]p = 0.5[/tex]

15 members:

This means that [tex]n = 15[/tex]

What is the probability that the final vote count is unanimous?

Either all vote no(P(X = 0)) or all vote yes(P(X = 15)). So

[tex]p = P(X = 0) + P(X = 15)[/tex]

In which

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{15,0}.(0.5)^{0}.(0.5)^{15} = 0.00003[/tex]

[tex]P(X = 15) = C_{15,15}.(0.5)^{15}.(0.5)^{0} = 0.00003[/tex]

So

[tex]p = P(X = 0) + P(X = 15) = 0.00003 + 0.00003 = 0.00006[/tex]

0.006% probability that the final vote count is unanimous.

Answer:

b) 0.0608

Step-by-step explanation:

As it is mentioned that the next two days i.e 24 hours, the probability of the rain is uniformly distributed

Therefore the rain probability is

[tex]= \frac{T}{24}[/tex]

where,

T = Length of the time interval

Plus, as we know that rain is independent

So let us assume the rain between the 8: 40 AM and 2: 35 PM on single day is P1 and the time interval is 5 hours 55 minutes

i.e

= 5.91666 hours long.

So, P1 should be

[tex]= \frac{5.91666}{24}[/tex]

= 0.2465

Now we assume the probability of rain on day 2 is P2

So it would be same  i.e 0.2465

Since these events are independent

So, the total probability is

[tex]= 0.2465 \times 0.2465[/tex]

= 0.0608

Hence, the b option is correct

Answer:

mean of the sample μ₁ = $0.27

Standard deviation of the sample σ₁ = $0.83

Step-by-step explanation:

Step(i):-

given mean of the population 'μ' = $19.67

Mean of the sample

                            [tex]= \frac{mean}{n} = \frac{19.67}{72} = 0.27[/tex]

Mean of the sample  μ₁ = 0.27

Step(ii):-

Given standard deviation of the  population  (σ) =  $7.02

Standard deviation of sample

                             [tex]= \frac{mean}{\sqrt{n} } = \frac{7.02}{\sqrt{72} } = 0.827[/tex]

Standard deviation of sample = 0.827≅ 0.83

Final answer:-

mean of the sample μ₁ = $0.27

Standard deviation of the sample σ₁ = $0.83

Step-by-step explanation:

sin²α − sin⁴α

Factor out sin²α.

sin²α (1 − sin²α)

Use Pythagorean theorem.

(1 − cos²α) cos²α

Distribute.

cos²α − cos⁴α

Answer:

''0 is neither a rational number nor an irrational number.''

Step-by-step explanation:

Zero is a rational number. Zero can be written as a fraction, where p/q = 0, where p = 0 and q is any non-zero integer. Hence, 0 is a rational number.

Answer:

Choice D.

Step-by-step explanation:

The number of points is obtained by the number of points of each multiple choice question times the number of multiple choice questions added to the number of points of each short answer question times the number of short answer questions.

Since the total number of points is 50, then the number of points from the multiple choice questions plus the number of points from the short answer questions add up to 50 points.

Answer: Choice D.

Answer:

D

Step-by-step explanation:

The number of points is 50, and short answer questions are 3 pts. Multiple choices are 1 pts.

So we have 3s+m=50

The question is incomplete. The complete question is as follows.

The city of Oakdale wishes to see if there is a linear relantionship between the temperature and the amount of electricity used (in kilowatts). Using the estimated regression equation found by using Temperature as the predictor variable, find a pont estimate Kilowatt usage when the Temperature is 90 degrees outside?

Temperature(x)                       Kilowatts(y)

        73                                         680

        78                                         760

        85                                         910

        98                                         1510

        93                                         1170

        83                                         888

        92                                         923

        81                                          837

        76                                         600

       105                                        1800

Answer: The point estimate is 1132.5 Kilowatts

Step-by-step explanation: Regression analysis is used to find an equation that fits the data. Once this equation is found, it's used to make predictions. One of the regressions is linear regression.

To find the linear regression model:

1) Create a table with the following: ∑y; ∑x; ∑xy; ∑x²; ∑y²;

2) Use these equations to find coefficients a and b:

a = (∑y)(∑x²) - (∑x)(∑yx) / n(∑x²) - (∑x)²

b = n(∑xy) - (∑x)(∑y) / n(∑x²) - (∑x)²

3) Substitute the coefficients into the equation of form: y = a + bx

For the table above, the linear regression equation is:

y = - 2004 + 34.85x

When Temperature is 90, i.e. x = 90:

y = - 2004 + 34.85*90

y = 1132.5

The estimate Kilowatt is 1132.5.

Answer: no, no, no, yes

Step-by-step explanation:

x=-3 is a vertical line. It goes straight up and down at x=-3. In order for the points to be on this line, the x-axis has to be -3. Looking at all the choices, all points are not a solution with the exception of (-3,0) which is right on the line.

Answer:

no no no yes

Step-by-step explanation:

i think

Answer:

Not a random variable

Step-by-step explanation:

The last book a person read in City A is not a random variable because it is not a number as there is no numerical description for the outcome of this experiment.

Thus, the last book read by someone in City A is not a random variable.

Answer:

not random

Step-by-step explanation:

Answer:

  (a) b = (4/7)c

  (b) Bill: 40 shingles/hour; Chip: 70 shingles/hour

Step-by-step explanation:

Let b and c represent Bill's and Chip's rates in shingles per hour, respectively. Then we have ...

  7b = 4c

  c - b = 30 . . . . shingles per hour difference in rates

(a) Bill's rate in terms of Chip's rate can be found by dividing the first equation by 7

  b = (4/7)c . . . . . Bill's rate is 4/7 of Chip's rate

__

(b) To find the rates, we can multiply the second equation by 7 and substitute using the first equation:

  7c -7b = 210

  7c -4c = 210

  c = 210/3 = 70

  b = (4/7)(70) = 40

Bill's rate is 40 shingles per hour; Chip's rate is 70 shingles per hour.

Answer:

A. 12

Step-by-step explanation:

If we split an equalateral triangle down, it will become 2 30-60-90 triangles. Remember your 30-60-90 triangle rules.

6√3 = x√3, so x = 6

2(6) (for hypotenuse) = 12

Since the hypotenuse is one side of the bigger triangle, we have our final answer of 12.

Answer:

  3

Step-by-step explanation:

Those wearing a shirt of another color are ...

  1 - 5/8 -1/4 = 8/8 -5/8 -2/8 = 1/8

of the total number of students in the classroom

  (1/8)×(24 students) = 3 students . . . . wearing another color

_____

Alternate solution

With the given information, you know ...

  (5/8)(24) = 15 . . . students wear blue

  (1/4)(24) = 6 . . . . students wear white

  24 -15 -6 = 3 . . . students wear another color

Answer:

2/5

Step-by-step explanation:

2 red, 3 yellow, 4 green, 6 blue marbles. = 15 marbles

P( blue) = blue / total

             =6/15

             =2/5

Answer:

The room dimensions for a minimum cost are: sides of 10 feet and height of 8.75 feet.

Step-by-step explanation:

We have a rectangular room with sides x and height y.

The volume of the room is 875 cubic feet, and can be expressed as:

[tex]V=x^2y=875[/tex]

With this equation we can define y in function of x as:

[tex]x^2y=875\\\\y=\dfrac{875}{x^2}[/tex]

The cost of wall paint is $0.08 per square foot. We have 4 walls which have an area Aw:

[tex]A_w=xy=x\cdot \dfrac{875}{x^2}=\dfrac{875}{x}[/tex]

The cost of ceiling paint is $0.14 per square foot. We have only one ceiling with an area:

[tex]A_c=x^2[/tex]

We can express the total cost of painting as:

[tex]C=0.08\cdot (4\cdot A_w)+0.14\cdot A_c\\\\C=0.08\cdot (4\cdot \dfrac{875}{x})+0.14\cdot x^2\\\\\\C=\dfrac{280}{x}+0.14x^2[/tex]

To calculate the minimum cost, we derive this function C and equal to zero:

[tex]\dfrac{dC}{dx}=280(-1)\dfrac{1}{x^2}+0.14(2x)=0\\\\\\-\dfrac{280}{x^2}+0.28x=0\\\\\\0.28x=\dfrac{280}{x^2}\\\\\\x^3=\dfrac{280}{0.28}=1000\\\\\\x=\sqrt[3]{1000} =10[/tex]

The sides of the room have to be x=10 feet.

The height can be calculated as:

[tex]y=875/x^2=875/(10^2)=875/100=8.75[/tex]

The room will have sides of 10 feet and a height of 8.75 feet.

Answer: 6811

Step-by-step explanation:

in this problem the values are 8800 and -2900 and the respective probabilities are 0.83 and 0.17

--

so the expected profit o# sum = (x*P(x))=8800*(0.83)+(-2900)*(0.17)=6811

Answer:

4.92% probability that the third strike comes on the seventh well drilled

Step-by-step explanation:

For each drill, there are only two possible outcomes. Either it is a strike, or it is not. Each drill is independent of other drills. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

20% chance of striking oil.

This means that [tex]p = 0.2[/tex]

What is that probability that the third strike comes on the seventh well drilled

2 stikers during the first 6 drills(P(X = 2) when n = 6)[/tex]

Strike during the 7th drill, with 0.2 probability. So

[tex]P = 0.2P(X = 2)[/tex]

In which

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 2) = C_{6,2}.(0.2)^{2}.(0.8)^{4} = 0.2458[/tex]

Then

[tex]P = 0.2P(X = 2) = 0.2*0.2458 = 0.0492[/tex]

4.92% probability that the third strike comes on the seventh well drilled

Answer: 15

Step-by-step explanation:

to find the area multiply the length by height

in this case it’s 5ft and 3ft

5 • 3 = 15

A=15