In: Statistics and Probability
The following time series shows the sales of a particular product over the past 12 months.
| Month | Sales |
|---|---|
| 1 | 105 |
| 2 | 135 |
| 3 | 120 |
| 4 | 105 |
| 5 | 90 |
| 6 | 120 |
| 7 | 145 |
| 8 | 140 |
| 9 | 100 |
| 10 | 80 |
| 11 | 100 |
| 12 | 110 |
(a)
Construct a time series plot.
(b)
Use α = 0.3 to compute the exponential smoothing forecasts for the time series. (Round your answers to two decimal places.)
| Month t | Time Series Value
Yt |
Forecast
Ft |
|---|---|---|
| 1 | 105 | |
| 2 | 135 | |
| 3 | 120 | |
| 4 | 105 | |
| 5 | 90 | |
| 6 | 120 | |
| 7 | 145 | |
| 8 | 140 | |
| 9 | 100 | |
| 10 | 80 | |
| 11 | 100 | |
| 12 | 110 |
(c)
Use a smoothing constant of α = 0.5 to compute the exponential smoothing forecasts. (Round your answers to two decimal places.)
| Month t | Time Series Value
Yt |
Forecast
Ft |
|---|---|---|
| 1 | 105 | |
| 2 | 135 | |
| 3 | 120 | |
| 4 | 105 | |
| 5 | 90 | |
| 6 | 120 | |
| 7 | 145 | |
| 8 | 140 | |
| 9 | 100 | |
| 10 | 80 | |
| 11 | 100 | |
| 12 | 110 |
Does a smoothing constant of 0.3 or 0.5 appear to provide more accurate forecasts based on MSE?
A smoothing constant of 0.5 is better than a smoothing constant of 0.3 since the MSE is greater for 0.5 than for 0.3.
A smoothing constant of 0.3 is better than a smoothing constant of 0.5 since the MSE is greater for 0.3 than for 0.5.
A smoothing constant of 0.3 is better than a smoothing constant of 0.5 since the MSE is less for 0.3 than for 0.5.
A smoothing constant of 0.5 is better than a smoothing constant of 0.3 since the MSE is less for 0.5 than for 0.3.
In: Statistics and Probability
The lifetime of a particular brand of tire is modeled with a normal distribution with mean μ = 75,000 miles and standard deviation σ = 5,000 miles.
a) What is the probability that a randomly selected tire lasts less than 67,000 miles?
b) If a random sample of 35 tires is taken, what is the probability that the sample mean is greater than 70,000 miles?
In: Statistics and Probability
The head of maintenance at XYZ Rent-A-Car believes that the mean number of miles between services is 2643 miles, with a standard deviation of 368 miles. If he is correct, what is the probability that the mean of a sample of 44 cars would differ from the population mean by less than 51 miles? Round your answer to four decimal places.
In: Math
A metropolitan transportation authority has set a bus mechanical reliability goal of 3,700 bus miles. Bus mechanical reliability is measured specifically as the number of bus miles between mechanical road calls. Suppose a sample of 100 buses resulted in a sample mean of 3,775 bus miles and a sample standard deviation of 325 bus miles.
a. Is there evidence that the population mean bus miles is more than 3,700 bus miles? (Use a 0.10 level of significance.) State the null and alternative hypotheses.
b. Find the test statistic for this hypothesis test.
c. The critical value(s) for this test statistic is(are)
d. Determine the p-value and interpret its meaning.
In: Statistics and Probability
answer all questions please!!!
The mean gas mileage for a hybrid car is
56
miles per gallon. Suppose that the gasoline mileage is approximately normally distributed with a standard deviation of
3.2
miles per gallon. (a) What proportion of hybrids gets over
62
miles per gallon? (b) What proportion of hybrids gets
52
miles per gallon or less?
left parenthesis c right parenthesis What(c) What
proportion of hybrids gets between
58
and
62
miles per gallon? (d) What is the probability that a randomly selected hybrid gets less than
45
miles per gallon?
LOADING...
Click the icon to view a table of areas under the normal curve.
(a) The proportion of hybrids that gets over
62
miles per gallon is
nothing.
(Round to four decimal places as needed.)
In: Statistics and Probability
I have to write a c program for shipping calculator. anything that ships over 1000 miles, there is an extra 10.00 charge. I have tried everything. no matter what I put, it will not add the 10.00. please help here is my code
#include <stdio.h>
#include <stdlib.h>
int main()
{
double weight, miles, rate, total;
printf("Enter the weight of the package:");
scanf("%lf", &weight);
if (weight > 50.0) {
puts("we only ship packages of 50 pounds or less.");
return 0;
}
if ( miles > 1000 ){
total = rate + 10.00;
printf("rate is $%.2lf \n", rate);
}
printf("Enter the amount of miles it would take:");
scanf("%lf", &miles);
if (weight <= 10.0)
rate = 3.00;
else
rate = 5.00;
printf("Shipping charge is $%.2lf \n", (int)((miles + 499.0) /
500.0) * rate);
if (miles >= 1000){
("shipping charge + 10.00");
}
system("pause");
}
In: Computer Science
III. A common utility function used to illustrate economic examples is the Cobb-Douglas function where U(X, Y)= XαYβ, where α and β are decimal exponents that sum to 1.0 (for example, 0.3 and 0.7).
a. For this utility function, the MRS is given by MRS = MUX=MUY = αY/βX. Use this fact together with the utility-maximizing condition (and that α+ β =1) to show that this person will spend the fraction of his other income on good X and the fraction of income on good Y— that is, show PXX/I = α, PYY/I = β.
b. Use the results from part a to show that total spending on good X will not change as the price of X changes so long as income stays constant.
c. Use the results from part a to show that a change in the price of Y will not affect the quantity of X purchased.
d. Show that with this utility function, a doubling of income with no change in prices of goods will cause a precise doubling of purchases of both X and Y.
In: Economics
The Lennard-Jones potential energy, U(x), is a function of “x” the separation distance between a pair of atoms in a molecule. It is frequently called the van der Walls potential between atoms for dipole-dipole interactions. The potential is
U(x) = C12/ x12 - C6/x6, [1]
Where
C12 = 1.51 x 10-134 J∙m12
C6 = 1.01 x 10-77 J∙m6.
(a) Determine the shape of the potential energy curve vs. distance of separation (x) between the atoms using Equation [1] by plotting the equation to scale on graph paper for “x” ranging from 0.3 – 1.0 nm.
(b) Calculate the equilibrium distance “xe” between the atoms at the minimum potential energy from Equation [1].
(c) Assuming the atoms are spherical balls with a spring between them, what is the spring constant (k) of the bond as atoms are pulled apart from their equilibrium position? Recall that F (force) = dU/dx, and F = kx.
In: Chemistry
Consider the system modeled by the differential equation
dy/dt - y = t with initial condition y(0) = 1
the exact solution is given by y(t) = 2et − t − 1
Note, the differential equation dy/dt - y =t can be written as
dy/dt = t + y
using Euler’s approximation of dy/dt = (y(t + Dt) – y(t))/ Dt
(y(t + Dt) – y(t))/ Dt = (t + y)
y(t + Dt) = (t + y)Dt + y(t)
New Value = change + current value
time ∆t = 0.1 ∆t = 0.0001 Exact Value %Relative %Relative
Error ∆t = 0.1 Error ∆t = 0.0001
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
In: Advanced Math