For a 30-60-90 triangle the sides always have the same relationship
Short leg = a
Long leg = a√3
Hypotenuse = 2a
BC is the short leg of ∆ABC
Given BC = 2
BC = a
Therefor
a = 2
AB = 2a = 4
AC = a√3 = 2√3
For ∆ACD
As above AC = 2√3
Since AC is the hypotenuse of ∆ACD
2a = 2√3
a = √3
CD = a = √3
AD = a√3 = 3
For ∆BCD
As above
BC = 2
CD = √3
Since BC is the hypotenuse of ∆BCD
2a = 2
a = 1
DB = a = 1
Answer:
a) 5.5
b) None
Step-by-step explanation:
The given data set is {96,89,79,85,87,94,96,98}
First we must find the mean.

We now find the absolute value of the distance of each value from the mean.
This is called the absolute deviation
{
}
{
}
We now find the mean of the absolute deviations

The least absolute deviation is 1.5. This is not within one absolute deviation.
Therefore none of the data set is closer than one mean absolute deviation away from the mean.
Answer:
5 and -4.5
Step-by-step explanation:
10/2=5
and -9/2=-4.5
-5 -4.5 -4 -3 -2 -1 0 1 2 3 4 5
Answer:
The value is 
Step-by-step explanation:
From the question we are told that
The mean is 
The standard deviation is 
The safest water level is between 7.2 and 7.8
Generally the probability that the selected pool has a pH level that is not considered safe is mathematically represented as

Here

Generally 
So
=>
From the z-table the probability of (Z < -1.5) and ( Z <1.5) are

and

So
So

=> 