Answer: 1692
Step-by-step explanation:
Formula to find the sample size :
Given : Confidence level : 
⇒ significance level =
z-value for 90% confidence interval (using z-table)=
Prior estimate of the population proportion (p) of customers who keep up with regular vehicle maintenance is unknown.
Let we take p= 0.5
Margin of error : E= 2%=0.02
Now, the required sample size will be :
Simplify , we get
Hence, the required sample size = 1692
Answer:
number 3
Step-by-step explanation:
Answer: (80% , 85%)
Step-by-step explanation:
We know that, confidence interval for population proportion is given by :-
(p-E , p+E)
, where p = sample proportion , E = Margin of error.
Given : Proportion of elementary school teachers who are female = 82%.
The article also states the maximum error of their estimate = 3%.
Then, the 90% confidence interval for the proportion of elementary school teachers who are female will be :
(82%-2% , 82%+3%)
= (80% , 85%)
Hence, the resulting 90% confidence interval for the proportion of elementary school teachers who are female = (80% , 85%)
9514 1404 393
Answer:
133 1/3 km/hour
Step-by-step explanation:
Average speed is computed as ...
average speed = (total distance)/(total time)
= (80 km +120 km +200 km)/(2/3 + 1 + 1 1/3 hour) = 400 km/(3 hour)
= 133 1/3 km/hour
Answer:
x = 15
Step-by-step explanation:
3x− 12 = 2x+ 3
3x-2x-12 = 3
x = 3+12
x=15
hope this helps! :)
