The minimum and maximum values of the coefficient of
determination r2 are, respectively,
A. 0 and 1
B. −1 and 1
C. −1 and 0
D. 0 and +∞
The following data represent a random sample of earwig density (x) and the proportion of males that have forceps (y).
|
Earwig Density |
Proportion of Males with Forceps |
|
0.25 |
0.05 |
|
5.3 |
0.1 |
|
12.6 |
0.67 |
|
22 |
0.19 |
|
25.4 |
0.04 |
|
32.3 |
0.53 |
Which of the following is the correlation coefficient?
A. 0.33
B. 0.17
C. 0.02
D. 0.8
Which of the following is the equation of the regression
line?
A. y^=0.0072x+0.1452
B. y^=0.0072+0.1452x
C. y^=0.3319+0.1101x
D. y^=0.1101x+0.3319
In: Statistics and Probability
Two types of flares are tested for their burning times (in min) and sample results are given below.
Part I : Test the claim that Brand X has a mean less than Brand Y. Use 0.05 significance level.
| Brand X | Brand Y |
| n1 = 35 | n2 = 40 |
| x1 = 19.4 | x2 = 15.1 |
| Population SD = 1.4 | Population SD = 0.8 |
Claim:
Null Hypothesis:
Alternative Hypothesis:
Calculator Screen Name in Ti 183:
test statistics:
Pvalue/alpha conversion
decision:
Conclusion:
Part II: Construct a 95% confidence interval for U1-U2. Interpret the interval.
Confidence interval name on TI 83
Interval
Interpret.
In: Statistics and Probability
The mean height of an adult giraffe is 18 feet. Suppose that the distribution is normally distributed with standard deviation 0.8 feet. Let X be the height of a randomly selected adult giraffe. Round all answers to 4 decimal places where possible.
a. What is the distribution of X? X ~ N(,)
b. What is the median giraffe height? ft.
c. What is the Z-score for a giraffe that is 20 foot tall?
d. What is the probability that a randomly selected giraffe will be
shorter than 17.9 feet tall?
e. What is the probability that a randomly selected giraffe will be
between 17.7 and 18.3 feet tall?
f. The 80th percentile for the height of giraffes
is ft.
In: Statistics and Probability
The expected return of market portfolio is 10%. The standard deviation of market portfolio is 20%. Risk free interest rate is 2%. There is an investor with mean-variance utility function Answer the following questions.
1) Calculate the optimal weight to be invested in the market portfolio for the investor with A=5 . Calculate the expected return and standard deviation of the optimal complete portfolio for the investor.
2) According to the CAPM, calculate the expected returns of two stocks (stock 1 and stock 2) with betas equal to 0.8 and 1.5 respectively.
3) Calculate the beta and expected return of the portfolio that invests 20%, 60%, and 20% on stock 1, stock 2, and the risk-free asset, respectively.
In: Finance
Q1) Two identical pucks collide on an air hockey table. One puck was originally at rest. If the incoming puck has a speed of 6.50 m/s and scatters to an angle of 30.0º,what is the speed of the second puck after the collision?
(You may use the result that θ1−θ2=90º for elastic collisions of objects that have identical masses.)
Q2)A block of mass m = 3.0 kg, moving on a frictionless surface with a speed 2.9 m/s makes a perfectly elastic collision with a block of mass M at rest. After the collision, the 3.0 kg block recoils with a speed of 0.8 m/s. In Fig. 1, the mass M (in kg) is closest to:
In: Physics
For a three-period binomial model for modeling the price of a stock, you are given:
Calculate the price of a three-year $100-strike European put option.
1.23
1.49
1.78
2.01
2.48
Please provide full explanation
In: Finance
The mean height of an adult giraffe is 18 feet. Suppose that the distribution is normally distributed with standard deviation 0.8 feet. Let X be the height of a randomly selected adult giraffe. Round all answers to 4 decimal places where possible.
a. What is the distribution of X? X ~ N(,)
b. What is the median giraffe height? ft.
c. What is the Z-score for a giraffe that is 21 foot tall?
d. What is the probability that a randomly selected giraffe will be shorter than 18.6 feet tall?
e. What is the probability that a randomly selected giraffe will be between 17.3 and 18.3 feet tall? f. The 75th percentile for the height of giraffes is ft.
In: Statistics and Probability
Consider the two (excess return) index-model regression results for stocks A and B. The risk-free rate over the period was 6%, and the market’s average return was 15%. Performance is measured using an index model regression on excess returns.
| Stock A | Stock B | ||||||||||
| Index model regression estimates | 1% + 1.2(rM − rf) | 2% + 0.8(rM − rf) | |||||||||
| R-square | 0.594 | 0.445 | |||||||||
| Residual standard deviation, σ(e) | 10.6% | 19.4% | |||||||||
| Standard deviation of excess returns | 21.9% | 25.5% | |||||||||
a. Calculate the following statistics for each stock: (Round your answers to 4 decimal places.)
b. Which stock is the best choice under the following circumstances?
In: Finance
The preparations of two aqueous solutions are described in the table below. For each solution, write the chemical formulas of the major species present at equilibrium. You can leave out water itself.
Write the chemical formulas of the species that will act as acids in the 'acids' row, the formulas of the species that will act as bases in the 'bases' row, and the formulas of the species that will act as neither acids nor bases in the 'other' row.
You will find it useful to keep in mind that
NH3
is a weak base.
|
In: Chemistry
A gas turbine unit has a pressure ratio of 5/1 and a maximum cycle temperature of 550⁰C. The turbine drives the compressor and an electric generator., the mechanical efficiency of the drive being 97%. The ambient temperature is 20⁰C and the isentropic efficiencies of the compressor and turbine are 0.8 and 0.83 respectively.
Calculate the power output in kilowatts for an airflow of 15kg/s. Calculate also the thermal efficiency and the work ratio. Neglect changes in kinetic energy, and the loss of pressure in the combustion chamber.
Take cp = 1.005 kJ/kg K and ɣ=1.4 for the compression process, and take cp = 1.15 kJ/kg K and ɣ=1.333 for all combustion and expansion processes.
In: Mechanical Engineering