Answer:
78.5
Step-by-step explanation:
Formula to find area of a circle: A= pi*raduis to the second power
3.14*
First you square the 5
You do this by multiplying 5 times itself
3.14*25
Then you multilpy 3.14 and 25
78.5
Answer:
29.5+/-1.11
= ( 28.39, 30.61)
Therefore, the 90% confidence interval (a,b) =( 28.39, 30.61)
Step-by-step explanation:
Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.
The confidence interval of a statistical data can be written as.
x+/-zr/√n
Given that;
Mean x = 29.5
Standard deviation r = 5.2
Number of samples n = 59
Confidence interval = 90%
z-value (at 90% confidence) = 1.645
Substituting the values we have;
29.5+/-1.645(5.2/√59)
29.5+/-1.645(0.676982337100)
29.5+/-1.113635944529
29.5+/-1.11
= ( 28.39, 30.61)
Therefore, the 90% confidence interval (a,b) =( 28.39, 30.61)
(x+b/2a)^2-(b^2-4ac)/2a=0
Step 2:
Re-write the expression:
(x+b/2a)^2=(b^2-4ac)/4a^2
Step 3:
get the square root of both sides:
x+b/2a=sqrt[(b^2-4ac)/4a^2]
Step 4:
Simplifying we get:
x+b/2a=sqrt[b^2-4ac]/2a
Step 5
Make x the subject:
x=-b/2a+/-sqrt[b^2-4ac]/2a
Answer:
B
Step-by-step explanation:
Substitute the given values for x and y into the expression
-
+ 
= 4 - 4 + 
= 0 + 
=
= 4 
Answer:
7
Step-by-step explanation:
I don't completely understand what you were asking, but if you were counting by 7's, 91 would be after 84 instead of just 90.