Answer:
The 95% confidence interval for the proportion of water specimens that contain detectable levels of lead is (0.472,0.766).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence level of 
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of 
.
In a sample of 42 water specimens taken from a construction site, 26 contained detectable levels of lead.
This means that 
95% confidence level
So 
, z is the value of Z that has a pvalue of 
, so 
.
The lower limit of this interval is:
The upper limit of this interval is:
The 95% confidence interval for the proportion of water specimens that contain detectable levels of lead is (0.472,0.766).
Answer:
130
Step-by-step explanation:
Times 40 & 3 to get 120.
Then as 1 is equal to 1/4 and 4 is equal to 4/4 which is a whole.
As 4 = 4/4 or 1 whole.
Count by 4 with your fingers until you get 40. Which is ten.
Then add 120+10 which equals to our answer that is 130.
Answer:
2045064
Step-by-step explanation:
Let b>a,
a+b=40 so we can say a=40-b
We are told that b-a=6.5, using a found above in the equation gives us:
b-(40-b)=6.5
b-40+b=6.5
2b-40=6.5
2b=46.5
b=23.25, and since a=40-b
a=40-23.25
a=16.75
So a=16.75 and b=23.25
check...
16.75+23.25=40, 40=40
23.25-16.75=6.5, 6.5=6.5
