Answer:
P(x>278) is 0.16
Step-by-step explanation:
We are given that a normal distribution has a mean of 266 and a standard deviation of 12.
Mean = 
Standard deviation =
We are supposed to find P(x > 278)
So, Formula : 

Z=1
Refer the z table for p value
p value = 0.8413
P(x<278) is 0.84
P(x>278)=1-P(x<278)=1-0.84=0.16
Option A is true
Hence P(x>278) is 0.16
Its <span>x=−<span>1 here the answer</span></span>
Answer:
Ratio =
= 
Step-by-step explanation:
The perfect squares from 1-30 are:
1, 4, 9, 16, 25
Total no. of perfect squares = five =5
Total no. of non perfect squares = 30-5 = 25
Ratio =
= 5 / 25 = 
Answer:

Step-by-step explanation:
Given
← factor the numerator and denominator
=
← cancel (x + 4 ) on numerator/ denominator
= 
Given that <span>cos a = 3/5 and it is in the first quadrant :
then:
a=arccos 3/5
but
cot </span>θ=1/tan θ
thus to evaluate our vale we shall obtain the value for height since
adjacent=3
hypotenuse=5
thus
using Pythagorean theorem:
c²=a²+b²
hence
5²=3²+b²
b²=25-9=16
b=4
thus
tan θ=opposite/adjacent
tan a=4/3
thus
cot a=1/(4/3)=3/4