Answer:
its too small :(
Step-by-step explanation:
Answer:
the world may never know
Step-by-step explanation:
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:
Step-by-step explanation:
According to the given question, a tire company has developed a new type of steel-belted radial tire. Extensive testing indicates the population of mileages obtained by all tires of this new type is normally distributed with a mean of 37,000 miles and a standard deviation of 3,887 miles.
Let us define X be the random variable shows that the mileages tires normally distributed with
mean
μ = 37000
standard deviation
σ
=3, 887
Therefore
X ~ (μ = 37000, σ =3,887)
The company wishes to offer a guarantee providing a discount on a new set of tires if the original tires purchased do not exceed the mileage stated in the guarantee. Therefore the guaranteed mileage be if the tire company desires that no more than 2 percent of the tires will fail to meet the guaranteed mileage is determined as:
P(X < k) = 0.02

From the standard normal curve 2% area is determined as -2.0537 and hence
If we consider z value at two decimal places then

Therefore the guaranteed 29032 mileage be if the tire company desires that no more than 2 percent of the tires will fail to meet the guaranteed mileage.
The area under the standard normal curve is determined as: