Discuss the differences between histograms, relative frequency histograms, time series graphs, and stem and leaf displays.
In: Math
A _________________ is an important characteristic related to the response variable which, when unaccounted for, may lead researchers to false conclusions about cause and effect.
Question 2 options:
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In a double-blind experiment conducted to study the effectiveness of a new drug to relieve the common cold, a participant was given a sugar pill. After taking the pill, she finds she can breathe more easily, and her condition substantially improved. Which of the following describes this phenomenon?
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Question 5 (1 point)
Statistics can be an ‘art’ as different statisticians may use different methods of analysis in answering questions pertaining to a study.
Question 5 options:
A) True | |
B) False |
Question 6 (1 point)
Researchers want to test a new type of surgical procedure. Individuals are randomly placed in one of two groups. Ten individuals receive the new surgery, while the other 10 individuals receive the old surgery as a control. The participants do not know which surgical procedure they receive. Researchers are aware of which individuals are placed in each group. Which of the following characteristics of a controlled experiment has not been satisfied?
Question 6 options:
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Question 7 (1 point)
Which of the following would not necessarily be considered one of the four principles of good practice in a controlled experiment?
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In: Math
I have a normal process (Anderson-Darling pvalue=.54 and skew=.3. The median
The R chart is out of control (1 outlier). This means that the process variability is unstable, and the control limits on the xbar chart are unreliable. The process is not stable over time. What if anything does this have to do with choosing the center of the distribution? Use the median in this instance. Outliers will not affect median as much as the mean. That is my best guess.
In: Math
Would you please demonstrate to me how to create dataset A and
dataset B,
where dataset A has a larger range but smaller standard deviation
than
dataset B. Then the reverse where data set A has a smaller range
and larger standard deviation than data set B.
In: Math
Suppose you own a fish restaurant and you believe that the demand for sea bass is distributed normally (that is, follows the bell-shaped curve) with a mean of 12 pounds and a standard deviation of 3.2. In summary, we express this as N(12,3.2).
1a. The notation N(12,3.2) means that
The mean (average) is 3.2 and the standard deviation is 12 |
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The mean is 12 and the standard deviation is 3.2 and the data follows a bell shape curve |
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The mean is 12 and the standard deviation is 3.2 and the data does not follow a bell shape curve |
10 points
Question 2
What is the z-score for 20 pounds of sea bass? You find the z-score by calculating (x-mean)/standard deviation
0.0062 |
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2.50 |
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0.9938 |
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0.25 |
10 points
Question 3
The number inside Table A associated with 2.50 is
2.50 |
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0.0062 |
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0.9938 |
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0.25 |
10 points
Question 4
The number in the table represents that area to the
Right |
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Left |
10 points
Question 5
So 0.9938 is the area associated with a Z score of
2.50 or more |
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2.50 or less |
10 points
Question 6
The probability that you will need 20 pounds or more of sea bass is
0.25 |
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0.0062 |
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0.9938 |
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2.50 |
10 points
Question 7
What is the z-score for 15 pounds of sea bass
0.94 |
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0.8264 |
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0.06 |
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-0.94 |
10 points
Question 8
What is the number inside table A associated with 0.94
0.8264 |
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0.1736 |
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0.94 |
10 points
Question 9
So 0.8264 is the area associated with a Z score of
0.94 or less |
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0.94 or more |
10 points
Question 10
The probability that you will need 15 pounds of sea bass or less is
0.1736 |
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0.94 |
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0.8264 |
10 points
Question 11
What is the probability that you will need between 15 and 20 pounds of sea bass
0.94 |
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0.8264 |
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0.1674 |
10 points
Question 12
What is the z-score associated with the 95th percentile of the standard normal curve
0.95 |
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1.65 |
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1.28 |
10 points
Question 13
How many pounds of sea bass are needed for the 95th percentile of sea bass demand
1.65 |
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7.28 |
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17.28 |
In: Math
"You ask students to identify European countries on a map. On average students will identify 10% of the countries correctly. A similar test for US states indicates a 45% success rate. Asking students to identify 7 European countries and 3 US states, what is the chance that students will correctly identify at least 50% of the countries/states?"
"You have a set of 100 batteries. 13 of these batteries are defective. Testing 25 batteries, what is the probability to find 3 or more of the 25 batteries failing?"
In: Math
In: Math
Genetic theory predicts that, in the second generation of a cross of sweet pea plants, flowers will be either red or white, with each plant having a 25% chance of producing red flowers. Flower colours of separate plants are independent. Let X be the number of plants with red flowers out of 20 plants selected at random from the second generation of this cross. (a) What is the probability distribution of X? [3] (b) Calculate: (i) the mean and standard deviation of X. [3] (ii) P( X > 8) [2] (iii) P( 4 ≤ X ≤ 10) [2] (c) If only 3 of the 20 plants had red flowers, would this be an unusual sample? Calculate a probability and use it to justify your answer
In: Math
In: Math
Problem 4: A large firm uses three different types (A, B, and C) of
raw materials to manufacture its product. Previous records show
that 25% of the manufactured products are produced using material
A, 50% using material B, and 25% using material C. If it is known
that 5% of the product made with material A are defective, 2% made
with material B are defective, and 5% made with C are
defective.
What is the probability that a product selected at random from this
firm will be defective?
If a product selected at random from this firm is found to be
defective, what is the probability that it was made from material
A.
In: Math
Question 2
Frasers Logistics operates a large fleet of trucks that transport goods on behalf of their clients. The trucks undergo regular scheduled maintenance as well as unscheduled maintenance when a problem occurs. Data about the maintenance expense is collected continuously and recorded by the admin staff of Frasers. Frasers do believe in updating their fleet of trucks on a continuous basis and hence has trucks in operation of various ages. They suspect that both the age of the truck as well as the distance covered in km in a particular year will have an impact on the maintenance costs of the trucks. The data for a particular size truck has been collected and is shown in the table below.
Truck |
Expense (E) |
Distance in km (K) |
Age in years (A) |
Truck |
Expense (E) |
Distance in km (K) |
Age in years (A) |
1 |
3529.80 |
16800 |
2 |
13 |
12201.75 |
47040 |
8 |
2 |
4563.75 |
17280 |
1 |
14 |
6409.80 |
43560 |
1 |
3 |
8137.95 |
37840 |
4 |
15 |
10899.75 |
20320 |
10 |
4 |
9294.15 |
39840 |
9 |
16 |
2695.20 |
14880 |
3 |
5 |
12588.15 |
49440 |
6 |
17 |
3402.15 |
12000 |
3 |
6 |
11903.25 |
44160 |
8 |
18 |
6540.60 |
31680 |
5 |
7 |
3471.90 |
12480 |
1 |
19 |
3844.50 |
36785 |
2 |
8 |
11993.70 |
47040 |
7 |
20 |
12056.70 |
47520 |
7 |
9 |
12157.95 |
26560 |
9 |
21 |
11266.80 |
46560 |
7 |
10 |
13732.95 |
48000 |
11 |
22 |
5701.65 |
31200 |
5 |
11 |
2623.95 |
10560 |
3 |
23 |
13628.40 |
50400 |
10 |
12 |
5530.80 |
21600 |
2 |
The Expense column reflects the full maintenance expense for that particular truck during the past financial year, the Distance column reflects the distance in km that the truck covered in the past financial year and the Age column reflects the age of the truck.
Use the data in the sheet named “Frasers” and use Excel and the Data Analysis add-in to perform linear regression analysis on the data to determine whether direct distance travelled (K) or age (A) or both should be used for estimating future maintenance expenditure. Specifically answer the following questions:
The remaining answers must be based on the model that you have selected.
In: Math
The expected number of births at a rural hospital is one per day. Assume that births occur independently and at a constant rate.
Use R to the draw the pmf of the number of births per day at this hospital.
Find the probability of observing at least 3 births in a day.
Find the probability of observing at most 5 births in a week.
At a larger hospital, the expected number of births per day is 17.4. Assume that births occur independently and at a constant rate. On average, how long do we have to wait until a birth at this hospital?
What is the distribution of the total number of births per day at both of these two hospitals (the sum of births at each of the hospitals)? State any assumptions that you are making.
In: Math
Test the hypothesis using the P-value approach. Be sure to verify the requirements of the test.
Upper H 0 : p equals 0.58 versus Upper H 1 : p less than 0.58H0: p=0.58 versus H1: p<0.58
n equals 150 comma x equals 81 comma alpha equals 0.01n=150, x=81, α=0.01
Is
np 0 left parenthesis 1 minus p 0 right parenthesis greater than or equals 10np01−p0≥10?
No
Yes
In: Math
it is claimed that the following data comes from a Poisson distribution with mean 5.
test the claim at a 0.01 level of significance
score | < = 3 | 4 | 5 | 6 | > = 7 | total |
frequency | 6 | 9 | 10 | 7 | 4 | 36 |
In: Math
Please answer the following: United Dairies, Inc., supplies milk to several independent grocers throughout Dade County, Florida. Managers at United Dairies want to develop a forecast of the number of half gallons of milk sold per week. Sales data for the past 12 weeks are:
Week |
Sales |
1 |
2,750 |
2 |
3,100 |
3 |
3,250 |
4 |
2,800 |
5 |
2,900 |
6 |
3,050 |
7 |
3,300 |
8 |
3,100 |
9 |
2,950 |
10 |
3,000 |
11 |
3,200 |
12 |
3,150 |
1. Compute four-week and five-week moving averages for the time series.
PLEASE USE EXCEL AND ANSWER EACH PART OF THE QUESTION. THANKS !
ANSWER- THAT'S WHAT I GOT SO FAR:
Average=> | 117.19 | 19,238.28 | 3.8% | 101.43 | 16300.00 | 3.21% | |
MAE | MSE | MAPE | MAE | MSE | MAPE |
In: Math