COMPLETING THE SQUARE (PROCESS):
Do a reverse factoring procedure to develop the following form of equation:
(t + a)^2 = b
where:
t = unknown variable
a = coefficient
b = coefficient
Then take square root of both sides to find value of unknown variable as follows:
t^2 + 10t = 75
(t^2 + 10t + 25) = 75 + 25
(t^2 + 5t + 5t + 25) = 100
(t + 5)(t + 5) = 100
(t + 5)^2 = 100
√(t + 5)^2 = √100
Two solutions exist:
+(t + 5) = 10
AND
-(t + 5) = 10
Thus:
t = 10 - 5 = 5
AND
t = -5 - 10 = -15
Answer:
t = 5
AND
t = -15
Answer:
P(45<X<81) = P(-3<z<3)=0.9974 or 99.74%
Step-by-step explanation:
Mean = 63
Standard Deviation =6
We need to find probability that X lies between 45 and 81 i.e P(45<X<81)
First we will find z-score for X=45 and X=81
For X=45 the z-score can be found using formula:
Putting values and finding z-score
For X=45, z-score is -3
For X=81 the z-score can be found using formula:
Putting values and finding z-score
For X=81, z-score is 3
Now finding the probability of P(-3<z<3)
It can be solved as:
P(-3<z<3)=P(z<3)-P(z<-3)
Looking at the z-score table to find
P(z<3)= 0.9987
P(z<-3)=0.0013
So, P(-3<z<3)=P(z<3)-P(z<-3)
P(-3<z<3)=0.9987 - 0.0013
P(-3<z<3)=0.9974
or P(-3<z<3)= 99.74%
So, P(45<X<81) = P(-3<z<3)=0.9974 or 99.74%
There’s no picture or anything.
Answer:
x = 19
Step-by-step explanation:
(5x+4)+(x-2)+(3x+7) = 180
5x+4+x-2+3x+7 = 180
9x+9 = 180
9x = 171
x = 171/9
x = 19
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