Consider a coin toss experiment and the following assets. A gives £200 if the first is heads, £50 for tails. B gives £200 if the second is heads and £50 for tails. C is half of A plus half of B. A and B are independent. Show that the expected value of each asset isthe same. Show that C reduces risk and explain why this is so. [Hint: You need to calculate E(A), E(B), and E(C). Also calculate the standard deviation (or risk) of returns from each asset]
In: Economics
A new vaccination is being used in a laboratory experiment to investigate whether it is effective. There are 282 subjects in the study. Is there sufficient evidence to determine if vaccination and disease status are related?
Vaccination Status Diseased Not
Diseased Total
Vaccinated 54 124 178
Not Vaccinated 71 33 104
Total 125 157 282
Step 1 of 8:
State the null and alternative hypothesis.
Step 2 of 8:
Find the expected value for the number of subjects who are vaccinated and are diseased. Round your answer to one decimal place.
Step 3 of 8:
Find the expected value for the number of subjects who are vaccinated and are not diseased. Round your answer to one decimal place.
Step 4 of 8:
Find the value of the test statistic. Round your answer to three decimal places.
Step 5 of 8:
Find the degrees of freedom associated with the test statistic for this problem.
Step 6 of 8:
Find the critical value of the test at the 0.025 level of significance. Round your answer to three decimal places.
Step 7 of 8:
Make the decision to reject or fail to reject the null hypothesis at the 0.025 level of significance.
Step 8 of 8:
State the conclusion of the hypothesis test at the 0.025 level of significance.
In: Statistics and Probability
I did an experiment in which a cart on wheels is getting pulled by a pulley hanging off the surface. The pulley has a 50g hanger which causes the motion. The cart is 300g and then in different trials added one 50g weight, two, three, and then four. The slope was 0 degrees. My question is: Describe (and show with pictures) what forces change for each of the different configurations used.
In: Physics
. In an online experiment, participants were asked to react to a stimulus. Upon seeing a blue screen, participants were instructed to press a key and the reaction time was measured in seconds. The same participant is also asked to press a key when seeing a red screen, with the reaction time measured. (The first color tested was randomly selected for each participant.) The results of 6 randomly sampled participants are below. Is the reaction time to the blue stimulus different from the reaction time to the red stimulus at the 1% level of significance? (assume the population differences are approximately normally distributed)
participant 1 2 3 4 5 6
blue 0.582 0.481 0.841 0.267 0.685 0.450
red 0.408 0.407 0.542 0.402 0.456 0.533
Conduct a full hypothesis test. Be sure to:
• state the test and calculator test
• check conditions
1. state the hypotheses
2. find the differences between the pairs, sample mean, sample standard deviation, degrees of freedom and calculate the test statistic
3. state the level of significance
4. find the p-value and draw/shade the graph
5. make a decision
6. write a conclusion
In: Statistics and Probability
3. An experiment consists of randomly rearranging the 10 letters
of the word
QUARANTINE
into a sequence of 10 letters, where all possible orders of these
10 letters are equally likely. Find the probability of each of the
following events:
(1) 2 the first three letters include no A’s;
(2) 3 the first three letters or the last three letters (or both)
include no A’s;
(3) 2 the fourth letter is the first A;
(4) 3 the first letter and the last letter are the same;
(5) 2 the word ‘QUARANTINE’ is obtained;
(6)3 the sequence contains the word ‘RAN’
In: Statistics and Probability
In a calorimetry experiment to determine the specific heat capacity of a metal block, the following data was recorded: Quantity Mass of the metal block 0.50 kg Mass of empty calorimeter + Stirrer 0.06 kg Mass of calorimeter + stirrer + water 0.20 kg Mass of water 0.14 kg Initial Temperature of metal block 55.5 ⁰C Initial Temperature of water and calorimeter 22 ⁰C Final Temperature of block- water system 27.4 ⁰C Take the specific heat capacity of water to be 4186 J/Kg °C. The calorimeter and stirrer are made of Copper. Specific heat capacity of Copper is 387 J/Kg °C. Ignore the mass of the stirrer. Use the data and the information given to: a) Calculate the specific heat capacity of the metal block. (Please show ALL work for full credit) b) From your result above, what is the metal block probably made up of? c) Calculate the final temperature of the block – water system if the mass of the water in the calorimeter is increased to 0.50 kg (the same as the mass of the metal block).
In: Physics
The following data was collected in a laboratory experiment conducted at 305.2 K.
A.) Determine the complete rate law for this simple chemical process A → B
| Time | Concentration |
| 0 | 4.804 |
| 0.5 | 3.26799191 |
| 1 | 2.279801588 |
| 1.5 | 1.573137404 |
| 2 | 1.047454686 |
| 2.5 | 0.713650161 |
| 3 | 0.52422989 |
| 3.5 | 0.366551798 |
| 4 | 0.218181335 |
| 4.5 | 0.183699478 |
| 5 | 0.132508896 |
| 5.5 | 0.097326158 |
| 6 | 0.033145439 |
| 6.5 | 0.036526291 |
| 7 | 0.005104128 |
| 7.5 | 0.017253798 |
| 8 | 0.01185835 |
| 8.5 | 0.008150117 |
| 9 | 0.025601488 |
| 9.5 | 0.016150157 |
| 10 | 0.002645956 |
| 10.5 | 0.018181463 |
| 11 | 0.018750139 |
| 11.5 | 0.020859016 |
| 12 | 0.020590393 |
| 12.5 | 0.01959423 |
| 13 | 0.019721118 |
| 13.5 | 0.000191672 |
| 14 | 0.000131734 |
| 14.5 | 0.01990946 |
| 15 | 0.019937773 |
B.) For the set of kinetic data in the problem above, if the rate doubles when the temperature increases to 415.4 K, what is the activation energy for the process?
In: Chemistry
A factorial experiment was designed to test for any significant differences in the time needed to perform English to foreign language translations with two computerized language translators. Because the type of language translated was also considered a significant factor, translations were made with both systems for three different languages: Spanish, French, and German. Use the following data for translation time in hours.
|
Language |
|||
|
Spanish |
French |
German |
|
|
System 1 |
7 |
14 |
15 |
|
11 |
18 |
19 |
|
|
System 2 |
8 |
13 |
14 |
|
12 |
15 |
20 |
|
Test for any significant differences due to language translator system (Factor A), type of language (Factor B), and interaction. Use a =.05.
In: Advanced Math
An experiment is performed to study the fatigue performance of a high strength alloy. The number of cycles to crack initiation is measured for twenty specimens over a range of applied pseudo-stress amplitude (PSA) levels. Use the data in the table provided to fit the following three regression models with y = Cycles and x = PSA (note the natural log transform of y for all models):
PSA (x) Cycles (y)
80, 97379
80, 340084
80, 246163
80, 239348
100, 34346
100, 23834
100, 70423
100, 51851
120, 9139
120, 9487
120, 8094
120, 17956
140, 5640
140, 3338
140, 6170
140, 5608
160, 1723
160, 3525
160, 2655
160, 1732
iii. A simple linear regression model with a logarithm transformation on PSA: lny=δ0+δ1∙ln(x) .
1) Using model (iii.), find a 95% confidence interval for the mean Cycles to crack initiation at a PSA of 130
In: Statistics and Probability
|
Air Voids |
Retained Strength (%) |
|||||||
|
Low |
106 |
90 |
103 |
90 |
79 |
88 |
92 |
95 |
|
Medium |
80 |
69 |
94 |
91 |
70 |
83 |
87 |
83 |
|
High |
78 |
80 |
62 |
69 |
76 |
85 |
69 |
85 |
d. What is the P value for the test? Test the hypotheses using the P value. Do you get the same answer as (d)? If your answer is different, clearly interpret it.
In: Statistics and Probability