Most vertebrates have testosterone, and have behaviors that are mediated by this hormone. Testosterone can be helpful to animals, by enhancing (e.g.) territory acquisition, or harmful, by (e.g.) causing physiological stress. When male blackbirds are exposed to other male blackbirds, their testosterone levels change. In order to understand the impacts of testosterone on male blackbirds, researchers followed a few individual males, to monitor testosterone changes after encountering another male.   A pre-exposure measurement was made (in nanograms/deciliter) and a post-exposure measurement was taken, data below. Researchers will test the hypothesis that pre-exposure testosterone levels are the same as post-testosterone levels.

(2 points) 1. Does this hypothesis test depend on a t distribution, a Z distribution, or a χ² distribution?

(2 points) 2. What are the df for the test you will do?

(2 points) 3a. Is this a one-tailed, or a two-tailed test?

(2 points) 3b. How would you rephrase the hypothesis test to make it the other way (for instance, if you chose a one-tailed test in 3a, how would you re-phrase my original question to make it a two-tailed test?)

(2 points) 4. What is the hypothesized difference?

(2 points) 5. Calculate your test statistic here:

(2 points) 6. Do you reject or fail to reject the null hypothesis?

(2 points) 7. How would you articulate your conclusion to my grandmother, who would not like to hear about rejecting (or failing to reject) null hypotheses, but would be interested to know about blackbirds?

!!!!!!ANSWER ALL!!!!

Conceptual Questions:-

6.         Why do descriptive statistics differ for variables with different levels of measurement?

7.         A researcher collects data on the ages of individuals in two separate samples of equal size and concludes that one sample’s distribution is extremely platykurtic and the other sample’s distribution is extremely leptokurtic. What conclusion (if any) can the researcher make about comparisons of the frequency of cases in the modal categories in the two samples? Why?

8.         If the z score corresponding to the length of one inmate’s prison sentence is 1.8 and the z score corresponding to the length of another inmate’s prison sentence is 2.5, what could you say about the severity of the first inmate’s sentence relative to the second inmate’s sentence?

9.         What is obtained when we calculate a confidence interval?

10.       If the area between two z scores of a frequency distribution accounts for 42.46 per cent of the sample, what is the likelihood that anyone in the sample falls somewhere outside of these two scores?

1 GenLabs has been a hot stock the last few years, but is risky. The expected returns for GenLabs are highly dependent on the state of the economy as follows:

Please calculate the expected return and standard deviation of the stock.

2. A year ago, an investor invested $4,000 in the stock of IBM, $4,000 in the stock of GE, and $2,000 in the stock of Microsoft. The rate of return is 10% for IBM, 12% for GE, and 15% for Microsoft. How much is the overall rate of return for the portfolio?

3. Consider a portfolio that is composed of the following two securities:                                        Security A    Security B

       Expected return   5%         10%

       Standard deviation     6%         12%

If you allocate 40% into A and 60% into B, how much is the expected return on the portfolio?

If you allocate 30% into A and 70% into B, how much is the expected return on the portfolio?

It has been suggusted that the highest priority of retirees is travel. Thus, a study was conducted to investigate the differences in the length of stay of a trip for pre- and post-retirees. A sample of 683 travelers were asked how long they stayed on a typical trip. The observed results of the study are found below.

With this information, construct a table of estimated expected values.

Now, with that information, determine whether the length of stay is independent of retirement using α=0.05α=0.05.

(a) χ2=χ2=

(b) Find the degrees of freedom:

(c) Find the critical value:

(d) The final conclusion is

A. There is not sufficient evidence to reject the null hypothesis that the length of stay is independent of retirement.
B. We can reject the null hypothesis that the length of stay is independent of retirement and accept the alternative hypothesis that the two are dependent.

a)Fill in the network diagram below

b-Clearly List your critical path

c-What is the shortest time need to complete the project (without expediting)?

d-To expedite the project by two weeks, which activities will you crash? Crashing cost?

find the indicated test statistic, from appropriate table:

1. F test, 99% confidence, v1 = 22, v2 =20 __________

2. F test, 97.5% confidence, v1 = 6, v2 = 20 _________

3. t test, 95% confidence, n = 12, two-tailed (note distinction between n and df) ________

4. z test, 95% condidence, one-tailed _________

5. μ= .7, x = 2 ________

6. P = .40, n = 4, x =1 (cumulative) ________

Answer the following short questions.

a. A rectangular block has a resistivity of ? and resistance of ?. If we scale it up in size by a factor of 2 in every direction, what is the new resistivity and resistance as a function of ? and ??

b. Small aircraft often use 24-V electrical systems rather than the 12-V systems used in automobiles, even though the electrical power requirements are roughly the same. This is because a 24-V system uses thinner wires and therefore weighs less. Explain this reasoning.

c. Show why the internal resistance of a source can be determined by dividing the open-circuit voltage by the short-circuit current.

d. Assuming each source has a small internal resistance, which circuit(s) would light up the light bulb? Which circuit(s) do you think would be likely to cause damage to the ammeter or voltmeter?

2. You have a battery, a voltmeter, and an ammeter, and you are asked to find the resistance perunit-length ?′ of a long spool of wire. You connect the voltmeter to the battery and it reads 3.2 V. You connect the battery to 20 m of the wire with the ammeter in series and it reads 9.6 A. You then connect a 50 m length of wire and the ammeter now reads 4.1 A.

a. What is the resistance per-unit-length of the wire and internal resistance of the battery?

b. If the wire is made from copper, with a resistivity of ? = 1.7×10−8 Ω⋅m, what is its diameter? c. What is the percentage of power dissipated within the internal resistance of the battery relative to the total power dissipated? Is this percentage larger, smaller, or the same as for the 50 m wire? 3. Consider the following circuit containing two sources, each with an internal resistance of 5 , and two load resistors, being 40  and 100 . a. How much current flows through this circuit and in what direction does it flow? b. What is the potential at a relative to ground? What is the potential at b relative to ground?

c. Where in the circuit is the potential the highest? Where is it the lowest?

d. Calculate the total power dissipated in both load resistors. 2 e. If the 100 Ω resistor is replaced by a short circuit, is the total power absorbed by the 40 Ω resistor greater than, equal to, or less than the total power initially absorbed by both resistors? f. How much power is supplied by each source? (Include the effect of the internal resistances.)

4. The average bulk resistivity inside the human body is about 5 Ω.m. The surface resistance of the skin varies considerably, from around 100,000 Ω for dry skin to 1000 Ω for wet skin. If the skin is broken and soaked in salt water, the skin resistance will even approach zero. Furthermore, the skin resistance can break down when voltages are high (above 500 V) or when voltages are changing (like under alternating current conditions). You can model the conducting path between the hands as three resistors in series. The first and third resistors represent the skin resistance while the second resistor represents the internal resistance of the body and can be modeled as a cylinder of diameter 10 cm and length 1.6 m.

a. Calculate the resistance between the hands for dry skin, wet skin, and broken soaked skin.

b. What potential difference would be needed for a lethal shock current of 100 mA in each of the three cases in part a (ignoring breakdown)?

c. Considering the chart below (taken from C. F. Dalziel, “Deleterious effects of electric shock,” 1961), how bad would a worst-case shock be from a 12 V DC car battery, your 50 V DC home phone line, and a 120 V 60 Hz wall outlet (i.e. with broken soaked skin)? Warning, don’t test any of these situations out at home! Despite your findings, there have been cases where people have died of an electric shock from a car battery. DC 60 Hz AC 10 kHz AC Effect Men Women Men Women Men Women Slight sensation on hand 1 mA 0.6 mA 0.4 mA 0.3 mA 7 mA 5 mA Perception threshold, median 5.2 mA 3.5 mA 1.1 mA 0.7 mA 12 mA 8 mA Shock, not painful and muscular control not lost 9 mA 6 mA 1.8 mA 1.2 mA 17 mA 11 mA Painful shock, muscular control lost by 0.5% 62 mA 41 mA 9 mA 6 mA 55 mA 37 mA Painful shock, let-go threshold, median 76 mA 51 mA 16 mA 10.5 mA 75 mA 50 mA Painful and severe shock, breathing difficult, muscular control lost by 99.5% 90 mA 60 mA 23 mA 15 mA 94 mA 63 mA Possible ventricular fibrillation 500 mA 500 mA 100 mA 100 mA n/a n/a

Periodic Inventory Using FIFO, LIFO, and Weighted Average Cost Methods

The units of an item available for sale during the year were as follows:

There are 16 units of the item in the physical inventory at December 31. The periodic inventory system is used. Determine the inventory cost using (a) the first-in, first-out (FIFO) method; (b) the last-in, first-out (LIFO) method; and (c) the weighted average cost method (round per unit cost to two decimal places and your final answer to the nearest whole dollar).

Probability expected value exercises questions:

1. The owner of an antique store estimates that there is a 50% chance she will make $3000 when she sells an antique cabinet, a 30% chance she will make $1550 when she sells the cabinet and a 20% chance she will break even when she sells it. What is the expected amount she will make when she sells the cabinet?
2. Three different people are selected at random and each given one gift card. The cards are from Panera Bread, Publix and Olive Garden. The first person chose chooses one card. The second person gets to choose one of the two remaining cards and the third person gets the third card. Determine the probability that
a) The Panera Bread card is chosen first
b) The Publix card is chosen first and the Olive Garden card is chosen next and the Panera Bread card is chosen last
c) The Publix card is chosen second
3. Ron has ten coins from Chile. four 1- peso coins, two 2- peso coin, one 5-peso coins one 10-peso coin and two 20-peso coins. He selects two coins at random without replacement. Assuming that each coin is equally likely to be selected, what is the probability he selects at least 1-peso one coin?
4. If a card is drawn from a standard deck of cards, what is the probability that the card is a red card, given that it is a face card? Use the table below for the probability questions

Jane Ericsson has just purchased a 62 square-meter down-town flat at NOK 3,500,000 financed with

20% of her own capital. Financing the rest of the purchase, a 20-year NOK 2,800,000 ordinary annuity

mortgage at 3.15% per year species end-of-month payments of interest including principal over the amortization period.

The rest payment is due one month from today. A two percent initiation fee charged by the lender requires Jane to increase her equity contribution by NOK 56,000.

It is commonly expected that down-town ats in Jane's neighborhood will appreciate by 2 percent per year over the next ten years.

Please provide numerical answers to the questions below:

(a) (7 points) Which monthly payment will amortize the mortgage-loan over the 20-year term?

(b) (7 points) What effective yield is Jane paying on the mortgage over the 20-year term?

Assume that Jane wants a 50% equity-share in her at after exactly 10 years (ie. 120 monthly payments).

Towards that end, she has received the lender's approval to adjust her monthly payment of interest and

principal.

(c) (8 points) Which monthly payment accommodates a 50% ownership in the at after 10 years?

(d) (8 points) Given the monthly payment calculated in (c), how many years does it take until

the loan is fully amortized (paid-down)?