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
USPshnik [31]
3 years ago
11

The data were gathered by the following procedure, reported in the study. "Between January and June 1998, parents of children ag

ed 2-16 years [...] that were seen as outpatients in a university pediatric ophthalmology clinic completed a questionnaire on the child’s light exposure both at present and before the age of 2 years." Was this study observational, or was it a controlled experiment? Explain.
Mathematics
1 answer:
WARRIOR [948]3 years ago
7 0

Answer:

This was an observational study.

Step-by-step explanation:

Given is that parents of children completed a questionnaire on the child’s light exposure both at present and before the age of 2 years.

This was an observational study since there is no treatment or control group.

We know that treatment, control groups or treatment groups are not specific to randomized control experiments.

You might be interested in
Someone help me asap!
Sergeeva-Olga [200]
Answer: 5/2

5/6 / 1/3 = 2.5

2.5 in fraction = 5/2
5 0
3 years ago
Read 2 more answers
Which expressions are equivalent to 7b(3+c) ?
Alex777 [14]

Answer:

The correct answer is B- 21b+7bc

Step-by-step explanation:

7b(3+c)

(7b)(3+c)

(7b)(3)+(7b)(c)

21b+7bc

4 0
3 years ago
Read 2 more answers
Which of the following represents the expression 3 3 3 3 5 5 5 5 5 5
Mice21 [21]

Answer:

Msjusjsudjdudududusuhdu

6 0
2 years ago
One positive number exceeds three times another positive number by 5. The product of the two numbers is 68. Find the number
kati45 [8]

Answer:12

Step-by-step explanation:

Let the numbers be a and b

a-3b=5 ........equation (1)

There product is :

ab=68 ..........equation (2)

From equation (1)

a-3b=5

Make a the subject of the formula

a=5+3b. ........equation (3)

Substitute equation (3) into equation (2)

(5+3b)b=68

3(b^2)+3b-68=0

The product is -204b^2(17 and -12)

(b+17)(b-12)=0

b=-17 or b=12

So the number is 12

6 0
4 years ago
Select all the equations on which the point (10,0) lies.
Makovka662 [10]

Answer:

  B, C

Step-by-step explanation:

Since y=0, you are looking for equations such that 10 times the coefficient of x is the constant in the equation.

  a) 5·10 ≠ 15

  b) 2·10 = 20 . . . . select this one

  c) 10 = 10 . . . . select this one

  d) 3·10 ≠ 13

  e) 4·10 ≠ 20

  f) 6·10 ≠ 50

8 0
2 years ago
Other questions:
  • John drove from house to work at an average speed of 30 mph, trip took 40 minutes. How far in meters is his house to work?
    12·1 answer
  • Find the lateral surface area and the total surface area for the pyramid .
    15·1 answer
  • Ana made 12 rainbow loom bracelets in 3 hours. how many can she make in 15 hours
    14·2 answers
  • What is the solution to this equation x -9=5​
    7·1 answer
  • Select all the expressions that could represent the volume of a box, which is a fourth degree polynomial in variables x and y.
    11·1 answer
  • On a coordinate plane, a line goes through (negative 12, negative 2) and (0, negative 4). A point is at (0, 6).
    5·2 answers
  • How does information about cell phones and cameras relate to the author’s main idea? It suggests Nessie is quite difficult to ca
    10·2 answers
  • PLS HURRY IM BEING TIMED
    9·1 answer
  • In a 3-digit number, the hundreds digit is one more than the ones digit and the tens digit is twice the hundreds digit. If the s
    5·1 answer
  • What is the value of the expression (2+4)3÷(26−4)?
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!