Answer:
C
Step-by-step explanation:
Because the more power the more battery. Therefore it is a function of time.
B)square root of 3
C) 2 timessquare root of 3
D)5
Answer:
I believe the third one
Step-by-step explanation:
Thanks.
Answer:
Altitude of the pile will increase by 16.56 cm per second.
Step-by-step explanation:
Sand is poured onto a surface at the rate = 13 cm³ per second
Or
It forms a conical pile with a diameter d cm and height of the pile = h cm
Here d = h
Volume of the pile cm³per sec.
Since h = d = 2r [r is the radius of the circular base]
r =
Since cm³per sec.
13 = [For h = 1 cm]
cm per second.
Therefore, altitude of the pile will increase by 16.56 cm per second.
To solve this problem, we first find the expression for the volume of the cone in terms of the height. We then differentiate this expression to get the relation between the rates of change of the volume and the height. By substituting the given values, we can find the rate of change of the height when the cone is 1 cm high.
The question is related to the application of calculus in Physics, specifically rates of change in the context of real-world problem involving a three dimensional geometric shape - a cone. The student asks how fast the altitude of a pile of sand is increasing at a given time if sand is being poured onto a surface at a constant rate and the pile forms a cone whose base diameter is always equal to its altitude.
We know that the volume of a cone is given by V = (1/3)πr²h, where r is the radius of the base and h is the altitude. Since in this problem the base diameter is always equal to its altitude, we have d = 2r = h, or r = h/2.
Replace r in the volume formula, yielding V = (1/3)π(h/2)²h = (1/12)πh³. Differentiate this expression with respect to time (t) to find the rate of change of V with respect to t, dV/dt = (1/4)πh² * dh/dt.
Given that sand is poured at a constant rate of 13 cm³/sec (that is, dV/dt = 13), we can solve for dh/dt when h = 1cm. Substituting the given values into the equation, 13 = (1/4)π(1)² * dh/dt, we find dh/dt = 13/(π/4) = 52/π cm/sec. Therefore, when the conical pile is 1 cm high, the altitude is increasing at a rate of 52/π cm/sec.
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Answer:
a) X=77 drivers
b) Power of the test = 0.404
c) Increasing the sample size.
Step-by-step explanation:
This is a hypothesis test of proportions. As the claim is that the speed monitors were effective in reducing the speeding, this is a left-tail test.
For a left-tail test at a 5% significance level, we have a critical value of z that is zc=-1.645. This value is the limit of the rejection region. That means that if the test statistic z is smaller than zc=-1.645, the null hypothesis is rejected.
The proportion that would have a test statistic equal to this critical value can be expressed as:
The standard error of the proportion is:
Then, the proportion is:
This proportion, with a sample size of n=150, correspond to
The power of the test is the probability of correctly rejecting the null hypothesis.
The true proportion is 0.52, but we don't know at the time of the test, so the critical value to make a decision about rejecting the null hypothesis is still zc=-1.645 corresponding to a critical proportion of 0.51.
Then, we can say that the probability of rejecting the null hypothesis is still the probability of getting a sample of size n=150 with a proportion of 0.51 or smaller, but within a population with a proportion of 0.52.
The standard error has to be re-calculated for the new true proportion:
Then, we calculate the z-value for this proportion with the true proportion:
The probability of getting a sample of size n=150 with a proportion of 0.51 or lower is:
Then, the power of the test is β=0.404.
The only variable left to change in the test in order to increase the power of the test is the sample size, as the significance level can not be changed (it is related to the probability of a Type I error).
It the sample size is increased, the standard error of the proprotion decreases. As the standard error tends to zero, the critical proportion tend to 0.58, as we can see in its equation:
Then, if the critical proportion increases, the z-score increases, and also the probability of rejecting the null hypothesis.
-distribution sill get taller and SD will decrease
-distribution will get shorter and SD will decrease
Distribution will get shorter and SD will increase
Answer:
Distribution will get taller and SD will decrease.
Step-by-step explanation:
Sample Size and Standard Deviation:
In a t-distribution, sample size and standard deviation are inversely related.
A larger sample size results in decreased standard deviation and a smaller sample size will result in increased standard deviation.
Sample Size and Shape of t-distribution:
As we increase the sample size, the corresponding degree of freedom increases which causes the t-distribution to like normal distribution. With a considerably larger sample size, the t-distribution and normal distribution are almost identical.
Degree of freedom = n - 1
Where n is the sample size.
The shape of the t-distribution becomes more taller and less spread out as the sample size is increased
Refer to the attached graphs, where the shape of a t-distribution is shown with respect to degrees of freedom and also t-distribution is compared with normal distribution.
We can clearly notice that as the degree of freedom increases, the shape of the t-distribution becomes taller and narrower which means more data at the center rather than at the tails.
Also notice that as the degree of freedom increases, the shape of the t-distribution approaches normal distribution.
In a t-distribution, as the sample size increases, the distribution becomes 'shorter', and the standard deviation decreases following the law of large numbers. The increased sample size reduces variability and introduces less deviation from the mean.
As the sample size increases for a t-distribution, the distribution tends to approach a normal distribution shape, which means the distribution will get 'shorter'. Additionally, the standard deviation (SD) would generally decrease as the sample size increases. This is due to the fact that when sample size increases, a smaller variability is introduced, hence less deviation from the mean.
To illustrate, imagine rolling a dice. If you roll it a few times, you may end up with quite a bit of variation. If you roll it a hundred times, however, the numbers should average out closer to the expected value (3.5 for a six-sided dice), and the standard deviation (a measure of variability) would decrease.
In conclusion, when the sample size increases, a t-distribution will get 'shorter' and SD will decrease. This concept is often referred as the law of large numbers.
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