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!
9514 1404 393
Answer:
D
Step-by-step explanation:
Multiplying the inequality by 2 will eliminate the fraction and give you ...
x ≤ 36
The "or equal to" part of the symbol means the end dot will be solid. The "less than" part of the symbol means the graph is shaded to the left of the end dot, which is at x=36. This description matches the graph shown below.
Answer: 19.2 miles is 30.72 km
Step-by-step explanation:
Since 5 miles is 8 km, divide 8/5 to find out how many miles is one kilometer.
8/5 = 1.6
Multiply 19.2*1.6 to find out how many kilometers 19.2 miles is.
19.2*1.6 = 30.72
(Note that when you search it up online, 19.2 miles is actually 30.9 km, because 5 miles isn't exactly 8km!)
5/10 and 1/2 are both equivalent ratios resulting in half of themselves you can multiply these by any numbers but they will stay as half ratios such as 1:2 x 6 it would be 6:12 divide it by 6 and you have a half
Answer:
1) <
2) >
3) =
4) 138.75%
5) 4.4%
6) 87%
7) 166
8) 119%
9) 22.5%
10) I don't know, sorry!
11) I can't do the rest in my head I am sorry
Step-by-step explanation:
1) Because 25% is 1/4, not 1/5; 20% would be 1/5, for future reference
2) Move the decimal to the right twice, then put a percent sign!
3) I'm actually not 100% sure on this one, but I believe it's equal to, though. I am so sorry I couldn't get you a clear enough answer.
4) 75 ÷ 100 (may wanna use a calculator)
I am running outta time I am SO SORRY :( just remember on 4-7 to estimate, 8-10 round to the nearest tenTH, and 11-14 find each number to the nearest WHOLE number!!!
