Answer:
One possible confound for the experiment is the attitude of the research assistants.
Step-by-step explanation:
A confounder simply means a variable that has impact in influencing both the dependent variable and independent variable, causing a spurious association.
So, we can conclude that the attitudes of the research assistants have positive and negative impacts in determining the reactions of both participants in the experiment.
The rudeness of a research assistant will negatively impact the response of the participant allocated to him/her.
The calmness of the other research assistant will positively impact the response of the participant allocated to him/her.
X= my age
500-3x=230
500-3x-230=230-230
270-3x=0
270-3x+3x=0+3x
270=3x
270/3=3x/3
x=90
you are 90 years old
Answer:
Toney buys the coat for $ 14.8.
Step-by-step explanation:
Cost of coat =$ 22
Mark up by 75 %
discount = 10 %
Let toney pay $ R for the coat.
So, according to the question
R + 75 % R = 1.75 R
Now the cost is
1.75 R - 15 % of 1.75 R = 22
1.75 R - 0.2625 R = 22
R = 14.8
So, he buy the coat for $ 14.8.
Answer:
270
Step-by-step explanation:
For any arithmetic sequence
nth term is given by
nth term = a + (n-1)d
where a is first term,
d is common difference
d is given by nth term - (n-1)th term
sum of n terms given by
sum = n/2(2a + (n-1)d)
________________________________________________
Given arithmetic sequence
-2,0,2,4,6,8...
first term a = -2
lets take third term as nth term and second term as (n-1)th term to find common difference d.
d = 2 - 0 = 2
using a = -2 , d = 2, n = 18
thus, sum of first 18 terms = n/2(2a + (n-1)d)
=18/2( 2*(-2) + (18-1) 2)
=9 ( -4 + 34)
=9 ( 30) = 270
Thus, sum of first 18 terms is 270.
