Hello Leyla! Could you provide details about the plumbing services? I’d be happy to help you in the comments.
Answer:
d. .00012 or 0.00012
Step-by-step explanation:
The variance of the population proportion formula is given as:
p(1 - p)/n
Where n = sample size
p = population proportion or p(hat)
n = 2000 people
p = 0.52
Variance of the population proportion = 0.52(1 - 0.52)/ 2000
= 0.52 × 0.48 /2000
= 0.2496 /2000
= 0.0001248
Therefore the Variance of the population proportion is approximately = 0.00012
Answer: A
Step-by-step explanation:
Confidence interval for the difference in the two proportions is written as
Difference in sample proportions ± margin of error
Sample proportion, p = x/n
Where x = number of success
n = number of samples
For the first treatment,
x = 35
n1 = 50
p1 = 35/50 = 0.7
For the second treatment,
x = 16
n2 = 40
p2 = 16/40 = 0.4
Margin of error = z√[p1(1 - p1)/n1 + p2(1 - p2)/n2]
To determine the z score, we subtract the confidence level from 100% to get α
α = 1 - 0.99 = 0.01
α/2 = 0.01/2 = 0.005
This is the area in each tail. Since we want the area in the middle, it becomes
1 - 0.005 = 0.995
The z score corresponding to the area on the z table is 2.576. Thus, the z score for 99% confidence level is 2.576
Margin of error = 2.576 × √[0.7(1 - 0.7)/50 + 0.4(1 - 0.4)/40]
= 2.576 × 0.10099504938
= 0.26
Confidence interval = 0.7 - 0.4 ± 0.26
= 0.3 ± 0.26
Option A is correct
Answer:
-5,3
Step-by-step explanation:
9514 1404 393
Answer:
£135.98
Step-by-step explanation:
It cost £135.98 for petrol in April.
