Answer:
A = 78.5 cm^2
Step-by-step explanation:
The area of a circle is given by
A = pi r^2
We know r =5 and pi = 3.14
A = 3.14 (5^2)
A = 3.14 (25)
A = 78.5 cm^2
12 bottles will be needed for a group that size
First, we go from small numbers. we know that both 68 and 80 are divisible by 2 which means that we can simplify the numbers dividing by 2. So it is 34/40. We know that again 2 is divisible by 34 and 40. So you divide 2 which gives 17/20. Now, no number is divisible by 17 and 20 so your answer is 17/20
Answer:
z²^30
Step-by-step explanation:
This is it enjoy.
Answer:
Sample size= 956
Step-by-step explanation:
Hello!
You need to construct an 80% CI for the average life of batteries. (hours)
The study variable is:
X: Lifespan of a battery.
X~N(μ; σ²)
The population standard devition isσ= 8
The interval to estimate the population mean follows the structure:
"Point estimator" ± "margin of error"
X[bar] ±
* (σ/√n)
X[bar] is the sample mean
* (σ/√n) is the margin of error of the interval (d)
Using the margin of error you can calculate the sample size:
d=
* (σ/√n)
n= (σ*
)²
n= 
n= 955.77 ≅ 956
I hope it helps!