week 3 project (1)
Course Project Phase Two
Pavel Garbuz
April 12th, 2017
Rasmussen College
1. Confidence interval
Confidence interval is a range which is used to provide an estimate of population mean. It is believed that the population mean would be from that range.
Point estimate is the value which we derive from a sample to give an estimate about the population.
The best point estimate is an estimate about the population mean. We derive this by finding the mean of the sample as a sample represents a population and there for its mean gives the best point estimator of population mean.
Normally samples represent a population. In theory it should be the same as a population but in reality the sample may have higher values and may not contain lower values and vice versa thus we don’t get the best point estimators of the population. To cater to this problem we use confidence interval by which we calculate a range in which the population mean is assumed to be present.
2. Best Point estimate of population Mean
BPE = sum of all ages / number or patients
BPE = 3709 / 60
BPE = 62 (61.82 round up)
3. Confidence interval
Confidence interval = 61.82 (+-) Z0.05/2 (S/ ((n)^(1/2))
= 61.82 (+-) 1.96 ( 8.92/ (601/2 )
= 61.82 - 2.257 , 61.82 + 2.257
= 59.56 > X > 64.077
4. Interpretation of confidence interval
In the research we were looking at the significance that old people tend to have particular infectious disease. We constructed a confidence interval to have an idea were the population mean lies. By constructing a confidence interval we have a point estimate of population mean. 95% of the samples would have a mean within the above range which is between 59.56 > age > 64.077.
5. Calculating confidence interval at 99%
61.82 (+-) 2.5758 (8.92/ (601/2)
= 58.85 > age > 64.79
Yes I did notice change in the interval as the range has increased as we can see in the calculation above.
Now the range for the point estimate has increase and as it at 99% confidence level we can say that its more accurate as 99 sample means would be within this sample. Whereas in 95% confidence we had 95 sample mean in that interval.
