A mad scientist develops a new memory pill and wishes to test it on a group of 11th grade students. He has a large number of sugar pills manufactured that look and taste exactly like the memory pills. He asks the manufacturer to prepare 50 envelopes, each containing a month's worth of doses of the memory pills, and 50 more envelopes with the same doses of sugar pills.The manufacturer then randomly labels the 100 envelopes with numbers from 00 to 99 and delivers them to the scientist. It has recorded which numbers go with the real pills, but it doesn't tell him. Which of the following adjectives describes this experiment?
A. Double-blind
B. Explanatory
C. Hawthorne
D. Blocked
E. Multi-factor
Answers
Answer: Double-blind
Step-by-step explanation:
The adjectives describes this experiment is " Double blind "
An experimental study in which neither the subjects nor the experimenters know which subjects are in the test and control groups during the actual course of the experiments is known as double blind.
In the given situation, the mad scientist and the manufacturer are not related or they are both blind to each other's experiment.
Related Questions
Jennifer cut a board 2 m long into two pieces. one piece is 24 m shorter than the other. find the length of each piece.. Piz help me!!!!!!!!!!!
Chester needs 2 feet of ribbon for an art project but his ruler only measures in centimeters. There are 12 inches in 1 foot and 2.54 centimeters in 1 inch
Melinda's lights went out. She has 3 pairs of red socks in her drawer 2 pairs of black socks and 5 pairs of white socks . What Is the minimum number of pairs she must remove from the drawer to ensure that she has a pair of each color? a. 3 b. 5 c. 7 d. 9 e. 10
Find the value of x in the equation 2(x – 3) 5x = 5(2x 6).
Answers
Answer:
Darlene's net proceeds after the broker fees are taken out is $8,279.
Step-by-step explanation:
From the question, the following can be obtained:
Basic cost of purchase of the stock = $20,000
Broker fee related to purchase = Basic cost of purchase of the stock * 1.5% = $20,000 * 1.5% = 300
Total cost of purchase of the stock = Basic cost of purchase of the stock + Broker fee related to purchase = $20,000 + 300 = $20,300
Selling price = $28,600
Broker fees related sales = 21
The net proceed can therefore be calculated as follows:
Net proceeds = Selling price - Broker fees related sales - Total cost of purchase of the stock = $28,600 - $21 - $20,300 = $8,279
Therefore, Darlene's net proceeds after the broker fees are taken out is $8,279.
Answers
Make sure the equation is in the form of [ Ax² + Bx + C = 0 ].
Yours is already in that form.
A = 1
B = 2
C = -2
Step #2:
The 'discriminant' for that equation is [ B² - 4 A C ].
That's all there is to it, but it can tell you a lot about the roots of the equation.
-- If the discriminant is zero, then the left side of the equation is a perfect square,
and both roots are equal.
-- If the discriminant is greater than zero, the the roots are real and not equal.
-- If the discriminant is less than zero, then the roots are complex numbers.
The discriminant of your equation is [ B² - 4 A C ] = 2² - 4(1)(-2) = 4 + 8 = 12
Your equation has two real, unequal roots.
Answers
Answers
Answer:
8
Step-by-step explanation:
20-7=13
13^1.50=8.66666666667
Round up with 8 or 9
What is the maximum height the ball will reach?
Find the number of seconds the ball is in the air when it reaches a height of 224 feet.
After how many seconds will the ball hit the ground before rebound?
Answers
after 3 seconds (just substitute t=3):
16(3)(9-3)=
16(3)(6)=
16*18=
288
maximum height: find the average of the roots:
the roots of 16t(9-t) are t=0 or t=9
since it's a parabola, the maximum is at t=4.5, at 324 ft
if its height is 224 feet, the equation is 224=144t-16t^2
16t^2-144t+224=0
divide by 16: t^2-9t+14=0
this can be factored as (t-2)(t-7)=0
the roots are t=2 and t=7, so the ball has been in the air for either 2 seconds or 7 seconds
the roots to 144t-16t^2 are 0 and 9, so the ball will hit the ground 9 seconds after being thrown
when you substitute a number in for t, it will tell you how high in the air the ball is after that many seconds. to find the height at three seconds, put in 3 for t.
h = -16*9 + 144*3
h = -144 + 3*144
h = 2*144 (i didn't want to multiply out 3*144 cause im lazy, so i combined like terms as if 144 was a variable.)
h = 288
after 3 seconds, the ball is 288ft in the air.
the maximum height is more complicated (and feel free to skip this paragraph if you think it'll confuse you more.) you could do it with a graphing calculator by graphing the function f(x)=-16x^2+144t and using a maximum feature. you could also use differential calculus to find it. but i think the best way is the way suggested by the person who answered before me, that is, finding the average of the roots. since the parabola's line of symmetry is perpendicular to the x-axis, that means the places the parabola intersects the x-axis (the roots) will be the same distance from the axis of symmetry and therefore the same distance from the vertex (the maximum point of the parabola.)
the roots of the parabola can be found this way:
h = -16t^2 + 144t
0 = -16t^2 + 144t
0 = t(-16t + 144)
0 = t or 0 = -16t + 144
16t = 144
t = 9
the roots are t=0 and t=9, therefore the line of symmetry (the middle of the parabola) is t=4.5. to find the maximum point of the parabola, plug 4.5 into the function for t and find the resulting height.
h = -16(4.5)^2 + 144(4.5)
h = -324 + 648
h = 324
so the maximum height happens at t=4.5 seconds, and the maximum height is 324ft.
to find how long it takes for the ball to be at 224 feet in the air, substitute 224 in for h:
h = -16t^2 + 144t
224 = -16t^2 + 144t
56 = -4t^2 + 36t divide by 4
14 = -t^2 + 9t divide by 4 again
t^2 - 9t + 14 = 0 rearrange
(t - 7)(t - 2) = 0
t = 7 and t = 2
at 2 seconds and again at 7 seconds, the ball will be 224ft in the air.
after how many seconds will the ball hit the ground? we already know this. the ball touches the ground just like the parabola touches the x-axis. to find when the ball hits the ground, we just have to find the root of the parabola, and we already know from earlier that the roots are t=0 and t=9. so, the ball will come into contact with the ground at 9 seconds.
hope this helped
Answers
Answer:Average rate of movement = 6.67 km/h
Step-by-step explanation:
Therefore, the average rate of movement of the volcanic ash for the first 15 hours is 6.67 kilometers per hour.