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2 years ago

Which pair of variables shows a clear causal link?

Mathematics

2 answers:

xxTIMURxx [149]2 years ago

8 0

The number of lights switched on in a room and the room's brightness.

LekaFEV [45]2 years ago

4 0

Answer:

The pair of variables that show a clear causal link are the number of lights switched on in a room and the room's brightness

Step-by-step explanation:

Clear casual link indicates two variables that have a completly and unequivocal relation, meaning that changes in one variable produce automatically and with no doubt a change in the other.

Case A does not have this link as these two variables have no relation at all. A person from certian state may have any type of academic degree.

Case B Cost of aviation fuel may be explained by other variables like international prices and flight duration may be explained also due to climate.

Case D- a person may have a pet even under low income levels.

Case C is the only adequate relation, as turning lights on will always increase room's brightness.

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Twelve flags are evenly spaced around a running track. Ryan started running at the first flag and took 30 seconds to reach the s

aniked [119]

Answer:

Ryan takes 6n+36m -42 seconds to reach the nth flag for the mth time.

Step-by-step explanation:

It takes Ryan to run from 1st to 6th flag in 30 seconds, so it takes him

30 * 6/3 = 36 seconds to make one complete round.

or it takes 6 seconds to run from one flat to the next.

To reach the nth flag (n=1,2,3,4,5, or 6)

Ryan takes 6(n-1) seconds.

To reach it the mth times, he needs to add 36(m-1) seconds.

So time it takes Ryan to reach the nth flag for the mth time takes

6(n-1) + 36(m-1)

= 6n - 6 + 36m - 36

= 6n+36m -42 seconds

3 0

2 years ago

Two types of flares are tested and their burning times are recorded. The summary statistics are given below: n = 35 n = 40 = 19.

marusya05 [52]

Answer:

C. 3.8 min < ?X - ?Y < 4.8 min

Step-by-step explanation:

Let both flares be X and Y

For X

n1 = 35

Bar x1 =19.4

D1 = 1.4

For Y

n2 = 40

Bar X2= 15.1

S2 = 0.8

√(x1²/n1) + (x2²/n2)

=√ (1.4²/35)+(0.8²+40)

= 0.2683

Critical value, t = 2.032

We now have to calculate margin of error

0.2683x2.032

= 0.545 this is approximately equal to 0.5

Bar x1 - bar X2

= 19.4 - 15.1

= 4.3

At 95% confidence level

4.3+-0.5

4.3+0.5= 4.8

4.3-0.5 = 3.8

Therefore the answer is 3.8min<X-Y<4.8min

5 0

2 years ago

1:Suppose we have a bag with $10$ slips of paper in it. Eight slips have a $3$ on them and the other two have a $9$ on them. Wha

3241004551 [841]

Answer:

Step-by-step explanation:

1 ) No of total slips after addition = 11

8 slip with 3 on it

3 slips with 9 on it

expectation value = probability of 3 x 3 + probability of 9 x 9

= (8 / 11) x 3 + (3 / 11) x 9

24 / 11 + 27 / 11 = 4.636

2 )

No of total slips after addition = 12

8 slip with 3 on it

4 slips with 9 on it

expectation value = probability of 3 x 3 + probability of 9 x 9

= (8 / 12) x 3 + (4 / 12) x 9

2 + 3 = 5

3 )

Let n be the required number

No of total slips after addition = 10+n

8 slip with 3 on it

2 + n slips with 9 on it

expectation value = probability of 3 x 3 + probability of 9 x 9

= (8 / 10+n ) x 3 + (2+n / 10+n ) x 9 = 6

24 + 18 + 9n / 10 + n = 6

42 + 9n = 60 + 6n

3 n = 18

n = 6

4 )

Let n be the required number

No of total slips after addition = 10+n

8 slip with 3 on it

2 + n slips with 9 on it

expectation value = probability of 3 x 3 + probability of 9 x 9

= (8 / 10+n ) x 3 + (2+n / 10+n ) x 9 = 8

24 + 18 + 9n / 10 + n = 8

42 + 9n = 80 + 8n

n =

n = 38

Minimum of 38 has to be added .

6 0

2 years ago

Compare and contrast the solutions of 2x-4>6 and 2x-4=6

elena55 [62]

2x-4=6
2x=6+4=10
x=5
for the inequality, however:
<span>2x-4>6
2x>6+4
2x>10
x>5</span>

8 0

2 years ago

Jen is on the platform of her boat. She sights the top of a lighthouse at an angle of 30° as shown below. She knows that the hei

Tema [17]

In mathematics, an equation is a statement that asserts the equality of two expressions, which are connected by the equals sign "=". The word ...

5 0

2 years ago