Which system matches the graph below?

san4es73 [151]

Answer:

Good ways to sample

Simple random sample: Every member and set of members has an equal chance of being included in the sample. Technology, random number generators, or some other sort of chance process is needed to get a simple random sample.

Example—A teachers puts students' names in a hat and chooses without looking to get a sample of students.

Why it's good: Random samples are usually fairly representative since they don't favor certain members.

Stratified random sample: The population is first split into groups. The overall sample consists of some members from every group. The members from each group are chosen randomly.

Example—A student council surveys 100 students by getting random samples of 25 freshmen, 25 sophomores, 25 juniors, and 25 seniors.

Why it's good: A stratified sample guarantees that members from each group will be represented in the sample, so this sampling method is good when we want some members from every group.

Cluster random sample: The population is first split into groups. The overall sample consists of every member from some of the groups. The groups are selected at random.

Example—An airline company wants to survey its customers one day, so they randomly select 555 flights that day and survey every passenger on those flights.

Why it's good: A cluster sample gets every member from some of the groups, so it's good when each group reflects the population as a whole.

Example—A principal takes an alphabetized list of student names and picks a random starting point. Every 20th student is selected to take a survey.

Bad ways to sample

Convenience sample: The researcher chooses a sample that is readily available in some non-random way.

Example—A researcher polls people as they walk by on the street.

Why it's probably biased: The location and time of day and other factors may produce a biased sample of people.

Voluntary response sample: The researcher puts out a request for members of a population to join the sample, and people decide whether or not to be in the sample.

Example—A TV show host asks his viewers to visit his website and respond to an online poll.

Step-by-step explanation:

In a statistical study, sampling methods refer to how we select members from the population to be in the study.

If a sample isn't randomly selected, it will probably be biased in some way and the data may not be representative of the population.

There are many ways to select a sample—some good and some bad.

4 0

3 years ago

. 3. Which of these ordered pairs is a solution to the linear inequality y – 4x ≤ –6? . . (Points : 1). A) (–2, 4). B) (1, –2).

Vikki [24]

We may answer the question above by substituting the values of the coordinates of the points in the choices to the x and y of the inequality.
A. (-2, 4) 4 - 4(-2) ≤ -6 12 ≤ -6 FALSE
B. (1, -2) -2 - 4(1) ≤ -6 -6 ≤ -6 TRUE
C (1, 3) 3 - 4(1) ≤ -6 -1 ≤ -6 FALSE
D. (2, 3) 3 - 4(2) ≤ -6 -5 ≤ -6 FALSE

The answer would be letter B.

7 0

3 years ago

Forty-seven percent of fish in a river are catfish. Imagine scooping out a simple random sample of 25 fish from the river and ob

Alexxx [7]

Question options:

The standard deviation is 0.0998. The 10% condition is not met because there are less than 250 fish in the river.

The standard deviation is 0.0998. The 10% condition is met because it is very likely there are more than 250 fish in the river.

The standard deviation is 0.9002. The 10% condition is met because it is very likely there are more than 250 fish in the river.

The standard deviation is 0.9002. The 10% condition is not met because there are less than 250 fish in the river.

We are unable to determine the standard deviation because we do not know the sample mean. The 10% condition is met because it is very likely there are more than 250 fish in the river

Answer:

The standard deviation is 0.0998. The 10% condition is met because it is very likely there are more than 250 fish in the river

Explanation:

Formula to calculate standard deviation = √p(1-p)/n

Given p= population proportion

n= sample size

From the question,

We are given p(population proportion of catfish in the river)= 0.47

n(sample size of fish collected from river) = 25

The standard deviation using the formula above = √0.47(1-0.47)/25

= 0.0998

The 10% condition demands that a sample size be not less than 10% of the population

To check if the 10% condition was met, we know that a river will likely have up to 250 fish in it and so,

10% of 250= 0.10×250=25 fish

Therefore the option B chosen is correct

8 0

3 years ago

15. Construct the slope-intercept form equation of the line passing through (-5,23) and (10,-5).

Radda [10]

Answer:

15y = -28 x + 205.

Step-by-step explanation:

Slope intercept form of equation is y = mx + c where m is slope and c is the y intercept.

Now slope of line passing through points (-5, 23) and (10, -5):

$m = \frac{y_{2} - y_{1} }{x_{2} - x_{1} } = \frac{-5 -23}{10 + 5} = \frac{-28}{15}$

Now equation of line:

y = mx + c

substituting the value of m in above expression,

$y = -\frac{28}{15} x + c$

Now, since the line is passing through the point (-5, 23) therefore, x = -5 and y = 23. By substituting these values in above equation,

$23 = -\frac{28}{15} \times (-5) + c$

$23 = \frac{28}{3} + c$

$c = 23 - \frac{28}{3} = \frac{69 - 28}{3} = \frac{41}{3}$

So equation of line in slope intercept form:

$y = -\frac{28}{15} x + \frac{41}{3}$

Further solving,

15y = -28 x + 205.

3 0

3 years ago

What is the value of the function when x = 4? y = 3x + 7

adelina 88 [10]

2x - 3y = 7 and -3x + y = 7..multiply Equation 2 by THREE and add to Equation 1
-9x + 3y = 21...........................watch the y's disappear
-7x........ = 28
x = -4
substitute -4 instead of x in either of the ORIGINAL equations

2x - 3y = 7
2(-4) - 3y = 7
-8 -3y = 7..........add 8 to both sides
-3y = 15
y = -5

im not sure

8 0

3 years ago

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