please help quickly !!

Answer:

a) The mean time it took the students, t ≈ 17.08 minutes

b) The fraction of the students that finished under 20 minutes is 2/3 of the students

Step-by-step explanation:

a) The mean of the frequency of grouped data is given as follows;

The given data arranged in tabular form is presented as follows;

\(\begin{array}{cccc}Time \, (t) \, in \, minutes & Midpoint, m & Frequency, f & Product \ m \cdot f \\5\leq t < 10 & 7.5 & 2 & 15 \\10\leq t < 15 & 12.5 & 9 & 112.5\\15\leq t < 20 & 17.5 & 5 & 87.5 \\20\leq t < 25 & 22.5 & 5 & 112.5 \\25 \leq t < 30 & 27.5 & 3 & 82.5 \\Sum & 87.5 & N = 24 & \Sigma (m\cdot f) = 410 \end{array}\)

Therefore, the mean time it took the students = ∑(f·m)/N = 410/24 = \(17\frac{1}{12}\)

The mean time it took the students, t ≈ 17.08 minutes

b) The number of the students that finished under 20 minutes = 2 + 9 + 5 = 16 students

The fraction of the students that finished under 20 minutes = 16/24 of  the = 2/3 of the students.

Answer:

see explanation

Step-by-step explanation:

The equation of a line in point- slope form is

y - b = m(x - a)

where m is the slope and (a, b) a point on the line

y - 5 = \(\frac{1}{2}\)(x + 2) ← in point- slope form

with slope m = \(\frac{1}{2}\) and (a, b) = (- 2, 5 ) ← point on line

Ricky has the number of stamps in the number of 15 stamps.

According to the question, the given parameters can be used to form the expression by using simplification method and the parameters are as follows:

Stamps for Ana: 8

Stamps for Ricky and Ana: 23

Given equation: 23 = r + 8

The equation formed by the simplification method is:  r + a = 23

Solving above two equations, we get a = 8 stamps and r = 15 stamps.

Hence, Ricky has the number of stamps in the number of 15 stamps.

What is simplification?

The word simplification is the procedure in which complicated expression can be written in a simpler form to make the calculation easy. This method is used to calculated the answers for the unknown quantity.

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Answer:

Step-by-step explanation: -1

Answer:C

Step-by-step explanation:

Change 6 1/3 into a mixed number so 19/3 then multiply 19 * 4 then divide by 4. So C

Answer:

25 1/3 C

Step-by-step explanation:

1) The statement of Lin is correct.

2) (a) When scale factor, k = 9, area of the new triangle = 8100 square inches

(b) When k = 3/4, area of the new triangle = 56.25 square inches.

Given that,

A triangle has area 100 square inches.

It's dilated by a factor of k = 0.25.

When the triangle is dilated by a scale factor of k, then, each of the base and height is dilated by the scale factor of k.

So new area of the triangle after the dilation with the original triangle having base = b and height = h is,

Area of new triangle = 1/2 (kb)(kh) = k² (1/2 bh) = k² × Area of original triangle

Here original area = 100 square inches.

k = 0.25

New area = (0.25)² 100 = 6.25 square inches

So the correct statement is that of Lin.

Mai may found the new area by just multiplying the scale factor with 100, instead of taking the square of the scale factor. That is why she got 25 square inches as the new area.

2) (a) When k = 9,

Area of the new triangle = 9² (100) = 8100 square inches

(b) When k = 3/4

Area of the new triangle = (3/4)² (100) = 56.25 square inches

Hence the areas are found.

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Convenience sampling is not a type of statistical sampling.

What is statistical sampling?

Sampling techniques in a statistical study refer to how participants are chosen from the population to participate in the study.

If a sample isn't chosen at random, it will likely be skewed in some way, and the results might not be generalizable.

Main body:

Simple random sample:

Each individual and group of individuals have the same chance of being selected for the sample. To obtain a basic random sample, one needs technology, random number generators, or some other type of chance mechanism.

stratified Random sample :

The population is first divided into sections. There are some people from each group in the overall sample. Each group's participants are chosen at random.

Cluster sampling:

Grouping the population first, a cluster random sample is taken. Every member of some of the groups makes up the overall sample. The selection of the groups is random.

Hence Convenience sampling is not a type of statistical sampling.

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hi

area of  circle is  π* radius²  

as radius is half diameter, and as diameter is  22 , so radius is  22 /2 = 11 cm

so area is  11²π    and  11² = 121 then   area is  121π

as it is say to use  3.14 for pi , then 121*3.14 =  379.94

but 379.94 is the area of the whole circle , and we only have half.  

so  :  379.94 / 2 = 189.97

area of  semi circle is  189.97

Answer:

400%

Step-by-step explanation:

percent = part/whole × 100%

percent = 72/18 × 100%

percent = 4 × 100%

percent = 400%

Answer: 400%

Answer:

400%

Step-by-step explanation:

The corresponding angle of ∠CBA is ∠NML.

Each point in a figure is transformed into a rotation by rotating it a certain amount of degrees around another point.

Given:
Two polygons are ABCDE and LMNOP.

And ABCDE is the rotation of about 180 of a figure LMNOP.

So, ABCDE ≅ LMNOP.

The side CB that corresponds to the side is NM.

And side BA that corresponds to the side is ML.

So, the interior angle of the polygon ABCDE, ∠CBA that corresponds to the interior angle of polygon LMNOP is ∠NML.

The corresponding angle of ∠CBA is ∠NML.

Therefore,  ∠CBA ≅ ∠NML.

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The probability of having an error when confidence limits are 3 standard deviations far from the mean is approximately 0.27.

Assume that the data is normally distributed. For a normal distribution, approximately 99.7% of the data is within 3 standard deviations of the mean.

As a result, if the lower and upper specification limits are 3 standard deviations away from the mean, they encompass 99.7% of the data.

As a result, there is only a 0.3% chance of an error. Since this is a two-tailed test, the probability of an error on each side is 0.15%

As a result, the probability of an error when the lower and upper specification limits are 3 standard deviations away from the mean is approximately 0.27.

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Answer:

A

Step-by-step explanation:

(x+yi)+(2(x+yi)+3i)=9

x+yi+2x+2yi+3i=9

3x+3yi+3i=9+0i

equating real and imaginary parts

3x=9,x=9/3=3

3y+3=0

3y=-3

y=-3/3=-1

x+yi=3-i

Answer:903.55

Step-by-step explanation:

The difference between the values 903.55 and 87.7 can be obtained using the subtraction operation on both values. Hence, the value of the difference is 815.85

Given the values :

To obtain the difference, we use the subtraction operation thus :

Therefore, the difference between 903.55 and 87.7 obtained by subtracting the two values from each other is 815.85

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Answer:

12. (-5)= -60

Step-by-step explanation:

Answer: -60

Step-by-step explanation:

the ( ) does not change the fact that the five is negative, so any number you multiply by it (that is positive) will be negative also.

Answer:

m = Y/x  -  b/x

Step-by-step explanation:

Answer:

y=1+0b

Step-by-step explanation:

Answer:

The last option

Step-by-step explanation:

You can find the slope by using this equation : y2-y1/x2-x1. We can choose any two y coordinates and any two x coordinates to find this. For instance, you can write this as -3-(-2.25)/0-(-1). Now, we can solve.

-3-(-2.25)/0-(-1)

-3+2.25/0+1

-0.75/1

-0.75

-0.75 in fraction form is -3/4.

I'm not quite sure how to calculate the y-intercept, but we know the slope, and that's all we need for this problem (the slope number is next to the x). This makes our answer the last option. Hope this helps!

Answer:

\((\frac{15}{2},6)\)

Step-by-step explanation:

Hey, Grace! Pleasure to meet you.

To solve this problem, I would strongly suggest for you to use the midpoint formula.

I have attached an image below of the formula used for plugging in values.

Confused? Let me show you! :)

M means midpoint by the way...

M = \((\frac{8+7}{2},\frac{10+2}{2}) = (\frac{15}{2} ,6)\)

There you go! Let me know if you have any questions, and best of luck with the rest of your assignment.

i. The maximum likelihood estimator, B for B is B_hat = n / sum(xi)

ii.  The maximum likelihood estimator of B is biased.

iii.  The maximum likelihood estimate of B for this sample is 0.077.

(i) The likelihood function is given by:

L(B) = f(x1; B) f(x2; B) ... f(xn; B)

= (B^n e^(-B*sum(xi))) / prod(xi)

Taking the natural logarithm and differentiating w.r.t. B, we get:

ln L(B) = n ln(B) - B sum(xi) - ln(prod(xi))

d(ln L(B))/dB = n/B - sum(xi)

Setting the derivative to zero and solving for B, we get:

B = n / sum(xi)

Therefore, the maximum likelihood estimator of B is B_hat = n / sum(xi).

(ii) To determine whether B is an unbiased estimator, we need to find the expected value of B_hat:

E(B_hat) = E(n / sum(xi))

= n / E(sum(xi))

Since X1, X2, ..., Xn are independent and identically distributed, we have:

E(Xi) = integral from 0 to infinity of xf(x) dx

= integral from 0 to infinity of x(x*e^(-x/8))/8 dx

= 8

Therefore, E(sum(Xi)) = n*E(Xi) = 8n, and:

E(B_hat) = n / (8n) = 1/8

Since E(B_hat) is not equal to B for any value of n, the maximum likelihood estimator of B is biased.

(iii) Substituting the given sample values, we have:

B_hat = 10 / (126 + 120 + 141 + 135 + 123 + 134 + 132 + 125 + 129 + 138)

= 0.077

Therefore, the maximum likelihood estimate of B for this sample is B_hat = 0.077.

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Answer:

The upper reason is your answer.....

We can conceptually isolate the strength of the evidence from the prior probability of the theory when we make observations first or form our hypotheses first. Correct option is C.

The concept of isolating the strength of evidence from the prior probability of the theory is known as Bayesian inference, which involves updating our prior beliefs about a theory or hypothesis based on the observed evidence.

This process can be done whenever we have some initial prior belief about the theory or hypothesis and then collect new evidence to test it.

In Bayesian inference, the strength of evidence is measured by the likelihood of the observed data given the theory or hypothesis, and the prior probability is the initial belief or probability assigned to the theory or hypothesis before the evidence is considered.

By combining these two sources of information, we can calculate a posterior probability or updated probability of the theory or hypothesis given the observed evidence.

Therefore, the answer is c) whether we make observations first or form our hypotheses first. The order in which we collect the evidence or form hypotheses does not affect our ability to conceptually isolate the strength of the evidence from the prior probability of the theory, as long as we use Bayesian inference to update our beliefs.

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Therefore , the solution of the given problem of percentage comes out to be the total amount of water is 100 ounces.

Any value that may be expressed as a fraction of 100 is referred to as a percentage in mathematics. The acronyms "pct.," "pct," or "pc" are also occasionally used. However, the "%" symbol is usually used to signify it. The proportional amount has no dimensions and is flat. Percentages can be viewed as fractions because their numerator is 100. To indicate that a number is a percentage, the percent symbol (%) must be used after the number.

Here,

Every day, Leilani consumes a total of 70 ounces of water. This implies that she consumes a total of 70 ounces of liquid every day before and after the ride.

She downs 14 ounces of water before her morning ride to be hydrated.

We would divide the quantity she drinks prior to the bike by the entire amount of water she consumes each day, then multiply the result by 100 to get the percentage of her daily water intake that she has before the ride. It develops

=> 14/70 × 100 = 20%\s=> 20

Thus, 20 equals 100 ounces of water in total.

As a result, the answer to the given 20-ounce problem is that there are 100 ounces of water in all.

Therefore , the solution of the given problem of percentage comes out to be the total amount of water is 100 ounces.

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The simplified expression of (5.1)(5.1^2)^4 is (5.1)^9

The expression is given as:

(5.1)(5.12)4

Rewrite the expression properly as follows:

(5.1)(5.1^2)^4

Rewrite the expression properly as follows:

(5.1)(5.1^2)^4 = (5.1) * (5.1^2)^4

Apply the power law of indices

(5.1)(5.1^2)^4 = (5.1) * (5.1^8)

Apply the power law of indices

(5.1)(5.1^2)^4 = (5.1)^(1 + 8)

Evaluate the sum

(5.1)(5.1^2)^4 = (5.1)^9

Hence, the simplified expression of (5.1)(5.1^2)^4 is (5.1)^9

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Answer:

2 minutes

Step-by-step explanation:

700/10 = 70

1 minute = 70 times

140/70 = 2 minutes

Answer:

2 minutes

Step-by-step explanation:

The heart beats 70 times per minute so 70+70=140.

The range of the function g(x) is [300, ∞)

In this question, we have been given that we have deposited $300 into a savings account that earns interest annually.

The function g(x) = 300(1.04)^x used to find the amount of money in the savings account, g(x), after x years.

We need to find the range of the function.

Since a savings account earns interest annually, x can have take values from 0 to infinity.

For x = 0 year,

g(0) = 300(1.04)^0

g = 300 * 1

g = 300

For x tends to ∞, the value of function would be ∞

Therefore, the range of the function g(x) is [300, ∞)

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The cosine of angle J is given as follows:

\(\cos{J} = \frac{14\sqrt{2}}{49}\)

The three trigonometric ratios are the sine, the cosine and the tangent of an angle, and they are obtained according to the rules presented as follows:

For the angle J in this problem, we have that:

Hence the cosine of angle J is given as follows:

\(\cos{J} = \frac{4}{\sqrt{98}} \times \frac{\sqrt{98}}{\sqrt{98}}\)

\(\cos{J} = \frac{4\sqrt{98}}{98}\)

\(\cos{J} = \frac{2\sqrt{98}}{49}\)

As 98 = 2 x 49, we have that \(\sqrt{98} = \sqrt{49 \times 2} = 7\sqrt{2}\), hence:

\(\cos{J} = \frac{14\sqrt{2}}{49}\)

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