1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
murzikaleks [220]
3 years ago
6

One way to measure self-discipline is the $1-now or $2-later test (which the researchers call the Delay Choice Task) in which we

see if a subject would decline to accept a dollar bill now when told they could wait a week and get two dollars. Highly self-disciplined adolescents outperformed their more impulsive peers on every academic-performance variable, including report card grades. Which of the following is correct?
A. This study is an experiment, since it was based on a random sample.
B. This study is an observation study since the researchers did not assign the students to one of the self-discipline categories.
C. This study is an experiment, since each subject was classified into a self-discipline category ($1-now or $2-later) and to report card grades.
D. This study is an experiment, since it was based on a random sample
Mathematics
1 answer:
denis23 [38]3 years ago
8 0

Answer:

A. This study is an experiment, since it was based on a random sample.

Step-by-step explanation:

Simple random sampling is a probabilistic sampling procedure that gives each element of the target population and each possible sample of a given size the same probability of being selected.

You might be interested in
The measurenicnt of the circumference of a circle is found to be 56 centimeters. The possible error in measuring the circumferen
BartSMP [9]

Answer:

(a) Approximate the percent error in computing the area of the circle: 4.5%

(b) Estimate the maximum allowable percent error in measuring the circumference if the error in computing the area cannot exceed 3%: 0.6 cm

Step-by-step explanation:

(a)

First we need to calculate the radius from the circumference:

c=2\pi r\\r=\frac{c}{2\pi } \\c=8.9 cm

I leave only one decimal as we need to keep significative figures

Now we proceed to calculate the error for the radius:

\Delta r=\frac{dt}{dc} \Delta c\\\\\frac{dt}{dc} =    \frac{1}{2 \pi } \\\\\Delta r=\frac{1}{2 \pi } (1.2)\\\\\Delta r= 0.2 cm

r = 8.9 \pm 0.2 cm

Again only one decimal because the significative figures

Now that we have the radius, we can calculate the area and the error:

A=\pi r^{2}\\A=249 cm^{2}

Then we calculate the error:

\Delta A= (\frac{dA}{dr} ) \Delta r\\\\\Delta A= 2\pi r \Delta r\\\\\Delta A= 11.2 cm^{2}

A=249 \pm 11.2 cm^{2}

Now we proceed to calculate the percent error:

\%e =\frac{\Delta A}{A} *100\\\\\%e =\frac{11.2}{249} *100\\\\\%e =4.5\%

(b)

With the previous values and equations, now we set our error in 3%, so we just go back changing the values:

\%e =\frac{\Delta A}{A} *100\\\\3\%=\frac{\Delta A}{249} *100\\\\\Delta A =7.5 cm^{2}

Now we calculate the error for the radius:

\Delta r= \frac{\Delta A}{2 \pi r}\\\\\Delta r= \frac{7.5}{2 \pi 8.9}\\\\\Delta r= 0.1 cm

Now we proceed with the error for the circumference:

\Delta c= \frac{\Delta r}{\frac{1}{2\pi }} = 2\pi \Delta r\\\\\Delta c= 2\pi 0.1\\\\\Delta c= 0.6 cm

5 0
3 years ago
What should the rule be for the table?
Law Incorporation [45]

Answer: it’s A

Step-by-step explanation:

8 0
2 years ago
Read 2 more answers
Pls help me on this​
NARA [144]
The answer is 10% because 10% of 40 is 4
7 0
2 years ago
What is the following quotient?<br> 35<br> 3<br> 12V5<br> o 40
Murrr4er [49]
C is the answer because it is
5 0
2 years ago
What is 35÷ into 7,140
sveta [45]
 the answer to 35 divided by 7,140=490196078
5 0
2 years ago
Read 2 more answers
Other questions:
  • Write the value of c that makes x^2+12x+c a perfect square trinomial.
    9·1 answer
  • How is the value of the ratio used to create the table
    11·1 answer
  • What is the correct way to write three hundred nine million, fifty-eight thousand, three hundred four?
    13·1 answer
  • a recipe requires 3.5 teaspoons of sugar to make a tart which equation shows the number of teaspoons of sugar , y , needed to ma
    14·1 answer
  • Given the function f(x) = −5x2 − x + 20, find f(3).
    5·2 answers
  • a store bought a diamond ring at a cost of 8000 and marked it up 25%.Tommy bought it and paid 15% sales tax.what was his total c
    11·1 answer
  • At a carnival luke bought 33 tickets . if he used 3 tickets trying to win the ring toss game,what is the ratio of tickets he has
    10·2 answers
  • What might be the units that you write in the blanks that make this true?
    9·1 answer
  • AABC is similar to AAXY by a ratio of 4:3. If BC = 24, what is the length of XY?
    15·1 answer
  • What is the measure of angle C?
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!