Name the sampling method used in each of the following situations:
a. A woman in the airport is handing out questionnaires to travelers asking them to evaluate the airport's service. She does not ask travelers who are hurrying through the airport with their hands full of luggage, but instead asks all travelers who are sitting near gates and not taking naps while they wait.
b. A teacher wants to know if her students are doing homework, so she randomly selects rows two and five and then calls on all students in row two and all students in row five to present the solutions to homework problems to the class.
c. The marketing manager for an electronics chain store wants information about the ages of its customers. Over the next two weeks, at each store location, 100 randomly selected customers are given questionnaires to fill out asking for information about age, as well as about other variables of interest.
d. The librarian at a public library wants to determine what proportion of the library users are children. The librarian has a tally sheet on which she marks whether books are checked out by an adult or a child. She records this data for every fourth patron who checks out books.
e. A political party wants to know the reaction of voters to a debate between the candidates. The day after the debate, the party's polling staff calls 1,200 randomly selected phone numbers. If a registered voter answers the phone or is available to come to the phone, that registered voter is asked whom he or she intends to vote for and whether the debate changed his or her opinion of the candidates.
Answer:
a) Convenient
b) Cluster
c) Stratified
d) Systematic
e) Random
Step-by-step explanation:
Samples may be classified as:
Convenient: Sample drawn from a conveniently available pool.
Random: Basically, put all the options into a hat and drawn some of them.
Systematic: Every kth element is taken. For example, you want to survey something on the street, you interview every 5th person, for example.
Cluster: Divides population into groups, called clusters, and each element in the cluster is surveyed.
Stratified: Also divides the population into groups. However, then only some elements of the group are surveyed.
Situation a:
Asks all from a single group(sitting passengers), that is, convenint sample.
Situation b:
First she separates the students by row, then from each row, she chooses all students. So this is Cluster sampling.
Situation c:
The manager separates the stores by location, and then in each location, random customers are chosen. This is an example of Stratified sampling.
Situation d:
Marks for every fourth patron, that is, every 4th element. So Systematic sampling.
Situation e:
People chosen at random, so Random sampling.
the first quartile of a data set is 33, and the third quartile is 53. which value in the data set is an outlier
Answer:
84
Step-by-step explanation:
53-33=20
53+1.5(20)=83 so anything above 83 is ur answer
Randomly select a customer that is a frequent shopper at our store. Randomly select a customer who does not know the store's location. Are these events mutually exclusive
Answer:
Yes, the events are mutually exclusive.
Step-by-step explanation:
Mutually exclusive events are events that can not occur at the same time.
For example: Turning left and turning right at the same time is not possible so the event is Mutually Exclusive.
Now consider the given information.
Randomly select a customer that is a frequent shopper at our store and randomly select a customer who does not know the store's location are mutually exclusive.
Because the customer either knows the location or not.
Yes, the events are mutually exclusive.
A snail crawls 9 millimeters per second. How many centimeters can it crawl in 50 seconds?
Answer:
450 millimeters
Step-by-step explanation:
Please let me know if you want me to add an explanation as to why this is the answer. I can definitely do that, I just wouldn’t want to write it if you don’t want me to :)
Andrea's dad ran 12 miles and 75 minutes on a treadmill if he runs at that rate how far could he run in 30 minutes
Answer: 187.5
Step-by-step explanation: Divide 75 by 12 to get 6.25 then multiply that by 30 to get 187.5.
I need these answered pls
Answer:
what exactly do we do here?
Step-by-step explanation:
if we are telling which ones are functions then it would be all of them except for 2, 5, and 6. the rest are functions. please comment if i got or attempted to get this correct.... sorry...
If Janet maintains the same driving rate can she drive more than 600 miles in 10 hours?Explain
Expression
a. The sum of 24 and 12
divided by 2
Answer:
18
Step-by-step explanation:
The sum of 24 and 12
divided by 2. means
24 + 12 / 2
36/2
=18
What is the value of y
O 12
O 1/3
O 6
O 2
In how many ways can the letters of
the word "COMPUTER" be arranged so that
i) all vowels are
always together?
ii) the relative positions of the vowels and
consonants are not changed?
Step-by-step explanation:
The vowels in the word "COMPUTER"
are O, U and E.
Part (i):
Number of ways = 5! * (6 * 3!) = 4,320 ways.
Part (ii):
Number of ways = 5! * 3! = 720 ways.
need help with the slope
Answer:
for sure it's a negative since the slop is going down.. other than that, that's all I can help you with since I'm barely learning about that too :)
xy(a²+1) - a(x²+y²)
Please help me
Answer:
a^2 xy+xy-ax^2-ay^2
Step-by-step explanation:
The table shows the amounts y (in tons) of waste left in a landfill after x months of waste relocation. Use the table to complete the statements.
x 0 3 6
y 24 18 12
It takes Response_________ months to empty the landfill.
Answer: it would take 1 year
Step-by-step explanation: scince it took 1/2 a year to get rid of half the waste it would take another 1/2 a year to get rid of the rest to it would take 1 year to get rid of all of the waste
What’s the answer to this? 4x-4=4x is it infinitive solution?
Answer:
16 ?
Step-by-step explanation:
Answer: There are no values of
x that make the equation true.
No solution
Step-by-step explanation:
SOMEONE PLEASE PLEASE HELP!!!!!
Answer:
1800
Step-by-step explanation:
Find the missing angle to the nearest degree.
19
32
degrees
Answer:
Step-by-step explanation: i think that it would be 32 degrees but im not quit shur
His income is 7x +6 everyday. What is his total income in x days?
Answer:
20
Step-by-step explanation:
7x+6=7 (2)+6=14+6=20
(let me know if it's wrong)
Subjective probabilities Group of answer choices are often inaccurate. are seldom used in management decisions. are usually identical to objective probabilities. all of the above.
Answer:
are often inaccurate.
Step-by-step explanation:
Subjective probability can be defined as the probability of an event happening based on the opinion, personal judgment, perception or experience of a person.
This ultimately implies that, subjective probabilities are not based evidence, quantitative results, facts, historical or empirical data (informations) and as a result, they are considered to be inaccurate.
Hence, subjective probabilities are often inaccurate.
An example of subjective probability is a financial advisor stating that, there is a 20% chance that the price of a security will increase by next week.
Christopher wants to estimate the mean amount of carbon dioxide that is emitted by burning 1\text{ L}1 L1, start text, space, L, end text of a new type of gasoline. He plans on burning 1\text{ L}1 L1, start text, space, L, end text at a time and measuring the resulting emissions. He'll repeat this process for a sample of nnn attempts and construct a confidence interval for the mean. He wants the margin of error to be no more than 202020 grams at a 90\%90%90, percent level of confidence. Preliminary data suggests that \sigma=50σ=50sigma, equals, 50 grams is a reasonable estimate for the standard deviation of the emissions from burning 1\text{ L}1 L1, start text, space, L, end text of this type of gasoline. Which of these is the smallest approximate sample size required to obtain the desired margin of error?
Answer:
The smallest sample size required to obtain the desired margin of error is of 17.
Step-by-step explanation:
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1-0.9}{2} = 0.05[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1-\alpha[/tex].
So it is z with a pvalue of [tex]1-0.05 = 0.95[/tex], so [tex]z = 1.645[/tex]
Now, find the margin of error M as such
[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
Which of these is the smallest approximate sample size required to obtain the desired margin of error?
The desired margin of error is 20, so [tex]M = 20[/tex]
We have that [tex]\sigma = 50[/tex].
The smallest sample size is n. So
[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]
[tex]20 = 1.645*\frac{50}{\sqrt{n}}[/tex]
[tex]20\sqrt{n} = 50*1.645[/tex]
[tex]\sqrt{n} = \frac{50*1.645}{20}[/tex]
[tex](\sqrt{n})^2 = (\frac{50*1.645}{20})^2[/tex]
[tex]n = 16.9[/tex]
Rounding up
The smallest sample size required to obtain the desired margin of error is of 17.
what is the slope of the line graphed below
Answer:
-1/2
Step-by-step explanation:
Slope = rise/run
rise = -1
run = 2
Therefore, the slope = -1/2
Express each ratio as a fraction. Write your answ
1) 3 hens to 18 chicks
a) Work out the value of angle x.
b) Give reasons for your answer.
Answer:
60 degrees
Step-by-step explanation:
The bottom and top horizontal lines are parallel. This means x and the bottom right angle in the triangle are the same. Because of the lines going through the triangle's sides we know the triangle's lengths are the same, making it an equilateral triangle. In an equilateral all angles are the same size: 60 degrees.
Which expression is equivalent to +7?
Which expression is equivalent to 5/6 divide to 7
Answer:
(5/6)/7!
5/(6*7!)=5/(6*7*6*5*4*3*2*1)=1/(6*7*6*4*3*2*1)=1/6048=0.0001653439
Step-by-step explanation:
The answer is 5/6x1/7
Are these correct please help
Answer:
x=x+1 is correct, -6x=-5(x-1)-1x is correct, 7(x-5)=x+13 is correct, x=x is correct, x+4=x+4 is correct.
5(x+2)=25 should go in one solution.
2x+2=2(x+1) should go into infinite solutions.
2x+3=2x+5 should go into no solution.
9x+1=9x should go into no solution.
2x+8=16 should go into one solution.
3x+1=31 should go into one solution.
Step-by-step explanation:
Explanation(s):
5(x+2)=25:
One value of x will equal 25, which is 3. You can solve this in two ways, calculations or graphing. I will show you both ways. You'll get 5x+10 from 5(x+2). Then you can subtract ten from both sides to isolate x, 5x=15. Then divide both sides by five to find what x equals, which is three. By graphing both the equations 5x+10 and y=25, you'll find that both of the lines intersect at (3,25), the x value of the coordinate is what x will equal, and there's only one intersection so there's only one solution.
2x+2=2(x+1):
The equation will be the exact same on both sides, which means all values of x will be a solution. If you were to graph both equations, they'd overlap perfectly, resulting in an infinite amount of intersections.
2x+3=2x+5:
The equation cannot be simplified any further, and 2x+5 is transformed two units above the equation 2x+3. If you were to graph both of these equations, they will never intersect for any value of x, which means no solutions.
9x+1=9x:
The equation cannot be simplified any further, and 9x+1 is transformed one unit above the equation 9x. If you were to graph both of these equations, they will never intersect for any value of x, which means no solutions.
2x+8=16:
Subtract eight from both sides, then divide both sides by two to get x=4. This means that there is only one solution for the equation. Alternatively, you could graph 2x+8 and y=16, and they will intersect at the point (4,16), which is only one solution.
3x+1=31:
Subtract one from both sides, divide by three to get x=10. There is only going to be one solution for the equation. Graph 3x+1 and y=31 to find that both the lines intersect at (10,31).
Find the value of x so that the ratios 9 : x and 15 : 40 are equivalent.
Answer:
x = 24
Step-by-step explanation:
x/9 = 40/15
x/9 = 8/3
x/9 = 24/9
x = 24
simply and write in exponential form
(1) p2*p-7
Answer:
[tex] {p}^{2} \times {p}^{( - 7)} = {p}^{(2 - 7)} = {p}^{ - 5}[/tex]
is the right answer.
2/3 divided by 1/7? 7/4 divided by 3/2? I NEED THIS IMMEDIATELY PLS!!
Answer:
1. 14/3
2. 7/6
Step-by-step explanation:
hope that helped you!
Consider the series 7/9+7/27+7/81+7/243
Answer:
=1 37/243
Step-by-step explanation:
the series is that the numerator is all 7
srry if its wrong i dont rlly understand what its asking
Answer:
= 1.1522....
Step-by-step explanation:
7/9 +7/27 +7/81 + 7/243
189 + 63 + 1,701 + 567
243. 19,683
= 252 + 2,268
243. 19,683
= 4,960,116 + 551,124
4,782,969
= 5,511,240
4,782,969
= 1.15
The letters from the word MATHEMATICS are placed in a hat. What is the probability of selecting an M and then selecting a T if the letters are selected at random and not replaced?
I'm Jeff Bezos. AMA (ask me anything)
Answer:
CAN I GET AMAZON GIFT CARD AND SOME MULLA THANKS LOVE YOU SUGAR ZZZADDY
Step-by-step explanation: