Name if the following are discrete or continuous variables. Also name if the scenario is ratio, ordinal, nominal, or interval The different heights of children in a fourth-grade class- The divisions of the American League in Major League Baseball- The number of pennies sitting in a jar- The time taken to deliver newspapers on a delivery route- Your age relative to the average age of other students in the class- The level of pain a patient indicates on a pain scale of 1-10- The counties of Ireland- The height of a pier above or below the surface of the water- The Nation Weather Service’s classification of Hurricanes as Categories 1, 2, 3, 4, or 5- Amount of water in an Olympic Swimming Pool-
Thanks!
In: Math
Name if the following are discrete or continuous variables.
Also name if the scenario is ratio, ordinal, nominal, or interval
The different heights of children in a fourth-grade class-
The divisions of the American League in Major League Baseball-
The number of pennies sitting in a jar-
The time taken to deliver newspapers on a delivery route-
Your age relative to the average age of other students in the class-
The level of pain a patient indicates on a pain scale of 1-10-
The counties of Ireland-
The height of a pier above or below the surface of the water-
The Nation Weather Service’s classification of Hurricanes as Categories 1, 2, 3, 4, or 5-
Amount of water in an Olympic Swimming Pool-
In: Math
In: Math
What is the BEST statistical method to use when you want to assess the association between a variable that is in ordinal scale and multiple variables that are in ratio/interval/ordinal scale.
In: Math
Use the distribution in the form of the stem-leaf plot.
Stem Leaves
1 1478
2 01237888
3 189
16/ The mid-point of the third class is
A./ 32 B/ 36 C/ 34.5 D/ 35
17/ The median is
A./ 24 B/ 23 C/ 25 D/ 5
18/ The relative frequency for the third class is:
A./ 20% B/ 50% C/ 66% D/ 40%
19/ The heights of a group of professional basketball players are summarized in the frequency distribution below. Find the mean height from this frequency table.
Height s (in) Frequency
70-72 4
73-75 6
76-78 8
79-81 2
A./ 75.2 in B/ 76.8 in
C/ 74.0 in D/ 77.5
in
20/ The temperatures ( in ºF ) in a room is recorded at the top of hours are
67, 68, 70 , 5, 77, 77, 78, 80, 78, 79, 74, 74. Choose best answer:
a/ It is a typo
b/ highest temperature is probably 95
c/ 5 is not an outlier
d/ 5 is an outlier
21/ The variance of 6 washing machines with
prices: $ 800, $784, $ 1,235, $860, $1,036 and $770
is
A/ 196.4 B/ 34,295.3 C/ 26,002.7 D/
185.2
22/ The coefficient of variation ( round to closest %) for
the set of data :
1, 3, 3, 5, 5, 6, 7, 8, 9 ,12, 15, 24 is
A 74% B/ 67% C/ 24% D/ 78 %
23/ Human body temperatures have the mean of 98.2º and a standard deviation of 0.6º.
Amy’s temperature can be described by z = 0.9. What is her temperature?
A/ 98.2º B/ 97.8º C/ 98.7º D/ 99.3º
24/ The upper bound for the outlier for the data
set
-11, 14, 22, 22, 22, 23, 31, 31, 42, 44, 44, 75 is
A/ 74.5 B/ 75 C/ 84 D/
68
25/ The box-plot of a data with 5- point summary 2, 6, 8, 11, 18
A/is positive skewed. B/ is negative skewed.
C/ is symmetric D/ perfect skewed
In: Math
Researchers use Elisa to test for Lyme disease. Lyme disease infects 0.0009 of the US population each year. The test has a detection rate of 0.98 and a false positive rate of 0.2.
a. What is the probability of a positive test?
b. What is the probability that a person with a positive result actually has Lyme disease?
In: Math
Green |
Red |
NIR |
In: Math
In: Math
1. A is called a palindrome if it reads the same from left and
right. For instance, 13631 is a
palindrome, while 435734 is not. A 6-digit number n is randomly
chosen. Find the probability
of the event that
(a) n is a palindrome.
(b) n is odd and a palindrome.
(c) n is even and a palindrome.
In: Math
Section 1
Tennis players often spin a racquet to decide who serves first. Th e spun racquet can land with the manufacturer’s label facing up or down. A reasonable question to investigate is whether a spun tennis racquet is equally likely to land with the label facing up or down. (If the spun racquet is equally likely to land with the label facing in either direction, we say that the spinning process is fair.) Suppose that you gather data by spinning your tennis racquet 100 times, each time recording whether it lands with the label facing up or down.
1.1.1
a. Describe the relevant long-run proportion of interest in words.
b. What statistical term is given to the long-run proportion you described in (a)?
c. What value does the chance model assert for the long-run proportion?
d. Suppose that the spun racquet lands with the label facing up 48 times out of 100. Explain, as if to a friend who has not studied statistics, why this result does not constitute strong evidence against believing that the spinning process is fair.
e. Is the result in (d) statistically significant evidence that spinning is not fair or is it plausible that the spinning process is fair?
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1.Assume that the heights of adult women are normally distributed with a mean height of 160 centimeters and the standard deviation is 8 centimeters.
What percentage of individuals have heights less than 160 centimeters?
2. Find the probability that a randomly selected individual has a height greater than 176 centimeters.
3. Find the probability that a randomly selected individual has a height less than 152 centimeters.
4. Can you determine the probability that a randomly selected individual has a height greater than 180 centimeters?
In: Math
Question 3 [25]
OK furniture store submit weekly records the number of customer
contacts contacted per week. A sample of 50 weekly reports showed a
sample mean of 25 customer contacts per week. The sample standard
deviation was 5.2. (Show all your works)
a) Compute the Margin of error at 0.05 significant level
[6]
b) Provide a 95% confidence interval for the population mean.
[4]
c) Compute the Margin of error at 0.01 significant level
[6]
d) Provide a 99% confidence interval for the population mean.
[4]
e) With a 0.99 probability, what size of sample should be taken if
the desired margin of error is 1.5
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Quality Air Conditioning manufactures three home air conditioners: an economy model, a standard model, and a deluxe model. The profits per unit are $61, $99, and $135, respectively. The production requirements per unit are as follows:
Number of Fans |
Number of Cooling Coils |
Manufacturing Time (hours) |
|
Economy | 1 | 1 | 8 |
Standard | 1 | 2 | 12 |
Deluxe | 1 | 4 | 14 |
For the coming production period, the company has 250 fan motors, 360 cooling coils, and 2600 hours of manufacturing time available. How many economy models (E), standard models (S), and deluxe models (D) should the company produce in order to maximize profit? The linear programming model for the problem is as follows:
Max | 61E | + | 99S | + | 135D | |||
s.t. | ||||||||
1E | + | 1S | + | 1D | ≤ | 250 | Fan motors | |
1E | + | 2S | + | 4D | ≤ | 360 | Cooling coils | |
8E | + | 12S | + | 14D | ≤ | 2600 | Manufacturing time | |
E, S, D ≥ 0 | ||||||||
The sensitivity report is shown in the figure below.
Optimal Objective Value = 19430.00000 | |||||||
Variable | Value | Reduced Cost | |||||
E | 140.00000 | 0.00000 | |||||
S | 110.00000 | 0.00000 | |||||
D | 0.00000 | 40.00000 | |||||
Constraint | Slack/Surplus | Dual Value | |||||
Fan motors | 0.00000 | 23.00000 | |||||
Cooling coils | 0.00000 | 38.00000 | |||||
Manufacturing time | 160.00000 | 0.00000 | |||||
Variable | Objective Coefficient |
Allowable Increase |
Allowable Decrease |
||||||
E | 61.00000 | 20.00000 | 11.50000 | ||||||
S | 99.00000 | 23.00000 | 13.33333 | ||||||
D | 135.00000 | 40.00000 | Infinite | ||||||
Constraint | RHS Value |
Allowable Increase |
Allowable Decrease |
||||||
Fan motors | 250.00000 | 40.00000 | 70.00000 | ||||||
Cooling coils | 360.00000 | 40.00000 | 110.00000 | ||||||
Manufacturing time | 2600.00000 | Infinite | 160.00000 | ||||||
Objective Coefficient Range | ||
---|---|---|
Variable | lower limit | upper limit |
E | ||
S | ||
D |
Optimal Solution | |
---|---|
E | |
S | |
D |
Right-Hand-Side-Range | ||
---|---|---|
Constraints | lower limit | upper limit |
Fan motors | ||
Cooling coils | ||
Manufacturing time |
In: Math
The following require calculating the probability of the specified event based on an assumed probability distribution. Remember to consider whether the event involves discrete or continuous variables.
You are measuring height of vegetation in a grassland using a Robel pole and a 5 m. radius. Based on 100 random samples from the grassland, you obtain a mean height of 0.6 m with a standard deviation of 0.04 m2.
a) What distribution is the appropriate reference for this problem?
b) Ninety percent of the samples are expected to be under what height? Use you will need to use the appropriate command in R of d<dist>, p<dist>, q<dist>, or r<dist> and use the appropriate values as arguments. Use help(command) to find out what these arguments are for your distribution, e.g., help(qbinom) will give you the help for this command.
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A survey is taken among customers of a fast-food restaurant to determine preference for hamburger or chicken. Of 200 respondents selected, 75 were children and 125 were adults. 120 preferred hamburger and 80 preferred chickens. 55 of the children preferred hamburger and 20 preferred chickens. Set up a 2x2 contingency table using this information and answer the following questions:
Age/ Food |
Hamburger |
Chicken |
Total |
Child |
|||
Adult |
|||
Total |
200 |
What is the probability that a randomly selected individual is an adult?
What is the probability that a randomly selected individual is a child and prefers chicken?
Given the person is a child, what is the probability that this child prefers a
hamburger?
Assume we know that a person has ordered chicken, what is the probability that this individual is an adult?
Are food preference and age statistically independent?
2) Three messenger services deliver to a small town in Oregon. Service A has 60% of all the scheduled deliveries, service B has 30%, and service C has the remaining 10%. Their on-time rates are 80%, 60%, and 40% respectively. Define event O as a service delivers a package on time.
Calculate P(A and O)
Calculate P(B and O)
Calculate P(C and O)
Calculate the probability that a package was delivered on time.
If a package was delivered on time, what is the probability that it was service A?
If a package was delivered 40 minutes late, what is the probability that it was service A?
3) The number of power outages at a nuclear power plant has a Poisson distribution with a mean of 6 outages per year.
What is the probability that there will be exactly 3 power outages in a year?
What is the probability that there will be at least 1 power outage in a year?
What is the variance for this distribution?
What is the mean power outage for this nuclear power plant in a decade?
In: Math