Answer:
d.
Step-by-step explanation:
Hello!
The objective of this test is to know if aerobic exercise modifies hippocampus activity. A random sample of 120 elderly men and women was taken and divided into two groups.
Group 1: Walked around a track three times a week.
Group 2: Did a variety of less aerobic exercises, including yoga and resistance training with bands.
After a year their brains were scanned showing that group 1 had an increase of 2% in their hippocampus and group 2 showed a decrease of 1.4%
a. True, this type of observational study can be the prelude to a more formal statistical study.
b. True, the explanatory variable is "type of exercise", it's the variable that the investigator suspects influence the hippocampus volume.
c. True, the objective of this experiment is to test if there is any modification on hippocampus volume, that's why the volume of the hippocampus was measured, before and after a year of exercise.
d. False, this is an observational study, you cannot establish a causal relationship between the two variables. Just inform you that there seems to be an association. To be able to generalize the results to all elderly population you need a more formal statistical experiment to support your conclusions.
I hope it helps!
Answer:
False
Step-by-step explanation:
It makes no sense......
Answer:
A stone is thrown straight up from the edge of a roof, 750 feet above the ground at a speed of 14 feet per second. A) Remembering that the acceleration due to gravity is -32 feet per second squared, how high is the stone 2 seconds later? B) At what time does the stone hit the ground? C) What is the velocity of the stone when it hits the ground?
Step-by-step explanation:
A stone is thrown straight up from the edge of a roof, 750 feet above the ground at a speed of 14 feet per second. A) Remembering that the acceleration due to gravity is -32 feet per second squared, how high is the stone 2 seconds later? B) At what time does the stone hit the ground? C) What is the velocity of the stone when it hits the ground?
Hey there!!
How do we find the equation of a line ?
Ans : We take the slope and the y - intercept and get them together.
How do you find slopes?
Ans - In order to find slop, we will need to use the slop formula which is
( y₂ - y₁ ) / ( x₂ - x₁ )
The two points shown in the above question are
( 4 , -8 ) and ( 8 , 5 )
y₂ = 5 , y₁ = -8 and x₂ = 8 , x₁ = 4
Now plug in the values:
( 5 + 8 ) / ( 8 - 5 )
13 / 3
Hence, the slope is 13/3
The basic formula : y = mx + b
Where b is the y-intercept and m is the slope.
We have found the slope, hence, the formula would become
... y = 13/3 x + b
Now take a coordinate and substitute it .
I will take ( 8 , 5 )
x = 8 and y = 5
Now plug in the values
... 5 = 13/3 × 5 + b
... 5 = 65/3 + b
Subtract 65/3 on both sides
... 5 - 65/3 = b
... -50/3 = b
Hence, the y-intercept is -50/3
Now plug in all the values to get the total equation...
The final equation : y = 13x/3 - 50/3
... y = 13x - 50 / 3
Hope my answer helps!!
Answer:
c. d = 5
Step-by-step explanation:
The difference in coordinates B and C is (14, 17) -(2, 1) = (12, 16). When the figure is scaled by 0.25, that difference becomes ...
0.25(12, 16) = (3, 4)
The length of a line segment with those coordinate differences is ...
d = √(3² +4²) = √25 = 5 . . . . matches selection c.
