Answer:
<em>5</em><em> players participated in the tournament.</em>
Step-by-step explanation:
In a small chess tournament, 20 matches were played.
Let us assume that n number of players participated in the tournament
As in each game 2 players play, so the number of ways they can play is,

As they played 2 games with every other participant in the tournament.
So the total number of games is,

But it is given to be 20, so





As
, so we get n=5.
Therefore, 5 players participated in the tournament.
The value of the z statistic for the considered data is given by: Option A: -3.87 approximately.
<h3>How to find the z score (z statistic) for the sample mean?</h3>
If we're given that:
- Sample mean =
- Sample size = n
- Population mean =
- Sample standard deviation = s
Then, we get:

If the sample standard deviation is not given, then we can estimate it(in some cases) by:

where
population standard deviation
For this case, we're specified that:
- Sample mean =
= 2.3 - Sample size = n = 15
- Population mean =
= 2.7 - Population standard deviation =
= 0.4
Thus, the value of the z-statistic is evaluated as:

Thus, the value of the z statistic for the considered data is given by: Option A: -3.87 approximately.
Learn more about z statistic here:
brainly.com/question/27003351
Answer:
Area = L²-5L
Step-by-step explanation:
Area = length * width
Length = L
Width = L - 5
Area = L * (L-5) = L²-5L
Let x = times in the pool
Let y = times in the basketball courts
42=3x+5y
x+y=12
Therefore y = 12-x
Subsitute for y
42 = 3x + 5(12-x)
42 = 3x + 60 -5x
Subtract 60
-18 = -2x
9 = x
The person used the pool 9 times.
Answer:
Below<3
Step-by-step explanation:
Type a : 55 75
Type b:48 22
= P(Male | Type B)> P(Male or Type B)