PHC 4069-Which of the following statements are true regarding

Question 1
1 pts

Which of the following statements are true regarding Type I
and Type II errors?
Type II error occurs when we fail to reject a true null
hypothesis.
Type II error occurs when we fail to reject a false
alternative hypothesis.
Type-I error occurs when we reject a true null
hypothesis
Type-I error occurs when we reject a true alternative
hypothesis.

Question 2
1 pts

The prevalence rate of Hypertension among US adults is
30%. We plan to draw a random sample of 65 people from
that population. What is the standard error of the sample
proportion of hypertension?
0.057
0.075
0.570
0.750

Question 3
1 pts

We selected a random sample of size 110 from a pool of
university students and asked whether they use Facebook on
a regular basis. Sixty replied yes. What would be your
estimation of the standard error of the sample proportion of

regular Facebook users based upon the given information?
0.002
0.047
0.064
0.247

Question 4
1 pts

To investigate the prevalence rate of Hypertension among
US adults, we drew a random sample of 70 adults from the
US and among them 12 people had hypertension. Please
construct a 95% confidence interval for the population
proportion of hypertension. Which one of the following
results is the closest to your answer? (Hint: use 1.96 as the
critical z-value).
[4.3%, 29.9%]
[6.3%, 27.9%]
[8.3%, 25.9%]
[10.3%, 23.9%]

Question 5
1 pts

A random sample of size 110 was selected from a pool of
university students and they were asked whether they use
Facebook on a regular basis. Sixty replied yes. What would
be your 90% confidence interval estimate of the population
proportion of regular Facebook users based upon the given
information? (Hint: use 1.65 as the critical z-value)

[42.6%, 66.4%]
[44.7%, 64.4%]
[46.7%, 62.4%]
[48.7%, 60.4%]

Question 6
1 pts

Which of the following statements are correct regarding
confidence intervals and sample size?
Confidence level has no impact on the size of
Confidence Intervals.
Greater confidence requires narrower Confidence
Interval.
Greater confidence requires wider Confidence
Interval.
Smaller sample size gives narrower Confidence
Interval.

Question 7
1 pts

It is known that the population standard deviation of the IQ
test results is 16. Assuming that we have a random sample
of 140, what is the standard error of the average IQ of a
sample of this size?
1.35
1.53
4
16

Question 8
1 pts

One hundred and ninety undergraduate students were
randomly selected from a university that has 47,000
students in total. Systolic blood pressure was tested on the
190 students. The sample standard deviation is 11.0 mmHg.
What is the estimated standard error of the sample mean?
0.08
0.80
1.08
1.80

Question 9
1 pts

It is known that the population standard deviation of the IQ
test results is 16. Assuming that we have a random sample
of 155 and a sample mean of 94, what would be your 90%
confidence interval estimate of the population mean? (Hint:
use 1.65 as the critical z-value)
[87.9, 100.1]
[89.9, 98.1]
[91.9, 96.1]
[93.9, 94.1]

Question 10
1 pts

Two hundred undergraduate students were randomly

selected from a university that has 47,000 students in total.
Systolic blood pressure was tested on the 200 students. The
sample mean is 118.0 mmHg and the sample standard
deviation is 11.0 mmHg. Please construct a 95% confidence
interval for the population mean of students' systolic blood
pressure. Which one of the following results is the closest to
your answer? (Hint: use 1.96 as the critical z-value)
[110.5, 125.5]
[112.5, 123.5]
[114.5, 121.5]
[116.5, 119.5]