In: Biology
A sociologist is interested in the relation between x = number of job changes and y = annual salary (in thousands of dollars) for people living in the Nashville area. A random sample of 10 people employed in Nashville provided the following information.
| x (number of job changes) | 6 | 3 | 5 | 6 | 1 | 5 | 9 | 10 | 10 | 3 |
| y (Salary in $1000) | 35 | 36 | 37 | 32 | 32 | 38 | 43 | 37 | 40 | 33 |
Σx = 58; Σy = 363; Σx2 = 422; Σy2 = 13,289; Σxy = 2,173
(a) Find x bar, y-bar, b, and the equation of the least-squares line. (Round your answers for x and y to two decimal places. Round your least-squares estimates to three decimal places.)
(b) Draw a scatter diagram for the data. Plot the least-squares line on your scatter diagram.
(c) Find the sample correlation coefficient r and the coefficient of determination. (Round your answers to three decimal places.)
| r = | |
| r2 = |
What percentage of variation in y is explained by the
least-squares model? (Round your answer to one decimal
place.)
%
(d) If someone had x = 9 job changes, what does the
least-squares line predict for y, the annual salary?
(Round your answer to two decimal places.)
In: Statistics and Probability
Which of the following changes will likely increase the solubility of a solid solute but decrease the solubility of a gaseous solute?
A. Increasing the temperature
B. Increasing the molecular mass of the solute
C. Decreasing the atmospheric pressure
D. Decreasing the concentration
In: Chemistry
A sociologist is interested in the relation between x = number of job changes and y = annual salary (in thousands of dollars) for people living in the Nashville area. A random sample of 10 people employed in Nashville provided the following information.
| x (number of job changes) | 6 | 7 | 3 | 6 | 1 | 5 | 9 | 10 | 10 | 3 |
| y (Salary in $1000) | 34 | 33 | 35 | 32 | 32 | 38 | 43 | 37 | 40 | 33 |
In this setting we have Σx = 60, Σy = 357, Σx2 = 446, Σy2 = 12,869, and Σxy = 2210.
(a) Find x, y, b, and the equation of the least-squares line. (Round your answers for x and y to two decimal places. Round your least-squares estimates to four decimal places.)
| x | = _____ | |
| y | = _____ | |
| b | = _____ | |
| ŷ | =______ | + ___ x |
(b) Find the sample correlation coefficient r and the coefficient of determination. (Round your answers to three decimal places.)
| r = _____ | |
| r2 = _____ |
What percentage of variation in y is explained by the
least-squares model? (Round your answer to one decimal
place.)
(c) Test the claim that the population correlation coefficient ρ is positive at the 5% level of significance. (Round your test statistic to three decimal places.)
t =
What is P value of test statistic
P value =
(d) If someone had x = 3 job changes, what does the
least-squares line predict for y, the annual salary?
(Round your answer to two decimal places.)
_______thousand dollars
(e) Find Se. (Round your answer to two
decimal places.)
Se =
(f) Find a 90% confidence interval for the annual salary of an individual with x = 3 job changes. (Round your answers to two decimal places.)
| lower limit | ___________ thousand dollars |
| upper limit | ___________ thousand dollars |
(g) Test the claim that the slope β of the population least-squares line is positive at the 5% level of significance. (Round your test statistic to three decimal places.)
t =
Find the P value of test statistic =
(h) Find a 90% confidence interval for β and interpret its meaning. (Round your answers to three decimal places.)
| lower limit ______ | |
| upper limit ______ |
In: Statistics and Probability
Considering the three classes of response of materials to changes in temperature, explain why it is a sudden change rather than an accelerating or gradual change that is important for the operation of a repeatable thermal cutout switch.
In: Mechanical Engineering
Life is not perfect. One reason for this is because the environment changes and adaptations lag. Which of the following best describes what this statement means.
|
Selection occurs in the parental generation. If the environment changes between generations offspring may no longer be best adapted to their environment. |
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Selection can only work with the genetic material present in a population. When the environment changes, new variation is needed and mutations that result in traits suitable to the current environment will take time to build up in the population. |
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Selection occurs in the parental generation. If the environment changes, parents may need to change their behavior in the new environment. These new adaptations would not have been passed onto previous offspring, resulting in a lag since some generations will not be best adapted to the new environment. |
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Two of the answers best describe this statement. |
Rose thorns are modified stems. The ancestors to our modern-day roses did not have thorns to protect them from herbivory. Which of the following would be the reasonable hypothesis for how natural selection drove the evolution of thorns on roses?
|
Ancestral rose stems had variable stem textures; from smooth to bumpy. Those with bumpy stems were less palatable to herbivores and so were consumed less frequently. Thus bumpy stemmed individuals reproduced more than smooth stemmed individuals and their offspring exhibited the parental bumpy stem texture. |
||
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Ancestral roses were all smooth-stemmed. A mutation arose that conferred thorn-like structures on rose stems. Individuals with the thorn mutation were less palatable to herbivores and so were consumed less frequently. Thus they reproduced more than smooth stemmed individuals and their offspring exhibited the thorn-like structure trait. |
||
|
Ancestral rose stems had variable stem textures; from smooth to bumpy. Those with bumpy stems were less palatable to herbivores and so were consumed less frequently. Thus bumpy stemmed individuals reproduced more than smooth stemmed individuals. |
||
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Ancestral rose stems had variable stem shapes; from rounded to angular Those with angular stems were less palatable to herbivores and so were consumed less frequently. |
In: Biology
discuss what the changes are in contemporary work labour markets and their impacts on the privileged occupational group
In: Economics
What is the percentage change in price for a zero coupon bond if the yield changes from 6% to 7%? The bond has a face value of $1,000 and it matures in 13 years. Use the price determined from the first yield, 6%, as the base in the percentage calculation.
In: Finance
A firm is considering several policy changes to increase sales. It will increase the variety of goods it keeps in inventory, but this will increase inventory by $11,500. It will offer more liberal sales terms, but this will result in average receivables increasing by $68,000. These actions are expected to increase sales by $815,000 per year, and cost of goods will remain at 70% of sales. Because of the firm’s increased purchases for its own production needs, average payables will increase by $36,500. What effect will these changes have on the firm’s cash cycle? (Use 365 days in a year. Do not round your intermediate calculations. Round your answer to 2 decimal places.)
In: Finance
McGilla Golf would like to know the sensitivity of NPV to changes in the price of the new clubs and the quantity of new clubs sold. The clubs will sell for $845 per set and have a variable cost of $405 per set. The company has spent $150,000 for a marketing study that determined the company will sell 60,000 sets per year for seven years. The marketing study also determined that the company will lose sales of 10,000 sets of its high-priced clubs. The high-priced clubs sell at $1,175 and have variable costs of $620. The company will also increase sales of its cheap clubs by 12,000 sets. The cheap clubs sell for $435 and have variable costs of $200 per set. The fixed costs each year will be $9,750,000. The company has also spent $1,000,000 on research and development for the new clubs. The plant and equipment required will cost $37,100,000 and will be depreciated on a straight-line basis. The new clubs will also require an increase in net working capital of $1,700,000 that will be returned at the end of the project. The tax rate is 25 percent, and the cost of capital is 10 percent. McGilla Golf would like to know the sensitivity of NPV to changes in the price of the new clubs and the quantity of new clubs sold. What is the sensitivity of the NPV to each of these variables?
In: Finance