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
uranmaximum [27]
3 years ago
9

In one study on the effect of argan oil on wrinkles, 125 subjects who acknowledged being long-time argan oil users had their wri

nkles compared with those of 125 people who had never used argan oil. In a second study, 75 subjects were chosen randomly to use argan oil and 75 were chosen to use a placebo. Identify the types of studies performed. (4 points)
Mathematics
1 answer:
brilliants [131]3 years ago
6 0

Answer:   The first study was an observational study whereas the second was a controlled experiment.

Step-by-step explanation:

A study that record the characteristics of a population by studying individuals in a sample, but does not manipulate variables of interest is known as an operational study. Like in the first study only effects have been noted.

A controlled experiment is an experiment where the variable of interest is directly manipulated by a scientist, in order to test a single variable at a time.

Like in the second study, the subjects were under the control of the experimenter, to test the effect of oil.

The first study was an observational study whereas the second was a controlled experiment.

You might be interested in
A vendor sells h hot dogs and s sodas. If a hot dog costs twice as much as a soda, and if the vendor takes in a total of d dolla
horrorfan [7]

Answer:

The expression for the cost of soda is 100 ×  \dfrac{\textrm d}{ \textrm 2h + \textrm s} cents

Step-by-step explanation:

Given as :

The quantity of hot dogs sold by vendor = h

The quantity of sodas sold by vendor = s

The total cost of hot dogs and soda = $ d

Let The price of hot dogs = $ x

And The price of soda = $ y

Now, According to question

The price of hot dogs is twice as much as soda

so, $ x = 2 × $ y

I.e   x = 2 y

and $ x h + $ y s = $ d

Or , 2 × $ y  h + $ y s = $ d

Or, y = \dfrac{\textrm d}{ \textrm 2h + \textrm s}

∵ 1 dollar = 100 cents

So, the price of  \dfrac{\textrm d}{ \textrm 2h + \textrm s} = 100 ×  \dfrac{\textrm d}{ \textrm 2h + \textrm s} cents

Hence The expression for the cost of soda is 100 ×  \dfrac{\textrm d}{ \textrm 2h + \textrm s} cents  Answer

5 0
3 years ago
The number of students using the ATM on campus daily is normally distributed with a mean of 240 and a standard deviation of 50.
damaskus [11]

Answer:

The probability is 0.080757

Step-by-step explanation:

We start by calculating the z-score

z-score = (x-mean)/SD/ √n

In this case;

x = 247 , mean = 240, SD = 50 and n = 100

z-score = (247-240)/50/√100

z-score = 7/50/10

= 7/5 = 1.4

So the probability we want to calculate is;

P( x > 1.4)

we can use the standard normal distribution table for this

P(x > 1.4) = 0.080757

4 0
3 years ago
MathsWatch The graph of y = f(x)
LuckyWell [14K]

Answer:

See below

Step-by-step explanation:

Translation about the y axis would be   y = f(-x)

Local max point of G  is seen as   -3,4     (NOT ASKED FOR)

<u>Local max for  -f(x) would be at   3, -4     as the negative sign flips around the x-axis     (this would be the max point flipped  BUT a MAX point would be  6,0   </u>

6 0
2 years ago
1/10 of blank is 8. PLEASE HELP ASAP!!! WILL MARK BRAINILEST
Oksi-84 [34.3K]

Answer:

2

Step-by-step explanation:

3 0
3 years ago
Read 2 more answers
Can someone help me with this?
Alenkasestr [34]

Answer:

(3/4)^2

=3×3/4×4

=9/16

8 0
3 years ago
Other questions:
  • What is the equation of the line that has a slope of 3 and goes through point (4, 7)?
    11·1 answer
  • Select the postulate of equality or inequality that is illustrated.
    5·1 answer
  • Simplify the expression: 15w-6w+14w^2
    7·2 answers
  • Help me yall!!......​
    13·1 answer
  • One of your responsibilities as a line cook is to
    9·1 answer
  • Find each unit rate. 1 ¼ hours in 5 days.
    10·1 answer
  • Luke bought a pair of jeans originally priced at $69.00. The jeans have been marked down 25%, and a sign posted on the rack wher
    7·2 answers
  • Evaluate the expression 10b/a if b = 6 and a = 2
    12·2 answers
  • 2 m<br> 2 in<br> 1.7 m<br> 3 m<br> 1 m<br> 1 m
    9·2 answers
  • (please help me out )In a recent year, 33.1% of all registered doctors were female. If there were 46,600 female registered docto
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!