Statistics review questions

In summary, the conversation is about practice questions from a class. The first question asks about the z-value used to construct a 95% confidence interval, and the correct answer is B. The second question is about the mean, median, and mode in a symmetric distribution, with the correct answer being B. The third question asks about which graph is best for displaying categorical data, with the correct answer being A. The fourth question is about when to use Yate's correction formula in a chi-square test, with the correct answer being D. The fifth question is about the type of data when investigating the status of patients with hypertension, with the correct answer being A. The sixth question is about the degrees of freedom in a comparison of two independent
  • #1
Jobless jack
1
0
Hi these are practice questions from our class.

can someone please help me by cheaking if i have done the correct answear ? if i am wrong could someone please provide the correct answear ? Thanks

1. The z-value that is used to construct a 95% confidence interval is
A 1.28 B 1.96
C 2.58 D 1.64

Ans: B

2. For a symmetric distribution
A. the mean is larger than the median.
B. the mean, median and the mode are equal.
C. the mean is smaller than the median.
D. the mode is the largest value.

Ans:B
3. Which graph can describe the frequency distribution of categorical variable?
A bar chart B pie chart
C histogram D scatter graph

Ans: A

4. In the chi-square test of 2×2 table, When should we choose the Yate’s correction formula?
A. n≥40 and 1≤O<5 B. 1≤O<5
C. 1≤E<5 D. n≥40 and 1≤E<5

Ans: D

5. In order to investigate the status of the patients with hypertension. The results show that there are 50 patients and 50 healthy people in 100 residents. Such kind of data is
A. numerical data B. multichotomus data
C. binary data D. ordinal data.

Ans: A

6. In the comparison of two-independent samples mean, df is
A n1-1 B n2-1
C n1+ n2-1 D n1+ n2-2

Ans A

7 The standard normal distribution
A is a special case of the normal distribution.
B. has a mean of 0 and a standard deviation of 1.
C. measures the distance from the mean in units of the standard deviation.
D all of the above.
Ans D

8 In the paired t-test, we assume in the null hypothesis that the distribution of the differences between the paired observation has a mean
A. equal to 1. B. equal to n - 1.
C.equal to 0. D. none of the above
ANs

9 In a random sampling (n = 400), we got a sample with the mean of 60 and the standard deviation of 10, then the standard error of the sample mean will be
A 0.5 B 30 C 0.025 D 0.15

ANs : D

10 The standard error of the mean
A is less than the standard deviation
B decreases as the sample size increases while standard deviation in definite.
C measures the variability of the mean from sample to sample
D all of the above

11 If we wish to determine whether there is evidence that the proportion of successes is higher in group 1 than in group 2 and we have obtained independent samples from the two groups, the appropriate test to use is
A t test B chi-square test
C F test D rank sum test
Ans : F test

12. When sample size increases,
A. standard error increases B. standard deviation increases
C. standard deviation decreases D. standard error decreases
Ans : C

13. Wilcoxon rank sum test was used to analyze the difference of the following two groups, the observations in the experimental group are 0, 0, 7, 14, 32, 40, while the observations in the control group are 0, 1, 2, 4, 4, 8. The “0”in the above groups should be ranked as

A. 2, 3, 1 B. 1.5, 1.5, 3
C. 2, 2, 2 D. 2.5, 2.5, 1
Ans D
 
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  • #2
Hi Jobless jack,

Welcome to MHB!

We prefer to have one question per thread and to focus on your work to see where we can help. So can you pick one problem to start with that you want to focus on, show us what you tried, and why you chose your answer? If you do that I and others would be happy to help. :)
 

1. What is the purpose of reviewing statistics?

Reviewing statistics allows scientists to check the accuracy and validity of the data collected in a study. It also helps to identify any potential errors or biases in the data collection process.

2. How do I choose the appropriate statistical methods for my study?

The appropriate statistical methods for a study depend on the type of data being collected, the research question, and the study design. Consulting with a statistician or conducting a literature review can help in determining the most suitable methods.

3. What is the difference between descriptive and inferential statistics?

Descriptive statistics are used to summarize and describe the characteristics of a data set, while inferential statistics are used to make predictions or generalizations about a larger population based on a sample of data.

4. How do I interpret the results of a statistical analysis?

Interpreting statistical results involves understanding the significance of the findings and determining if they support or reject the research hypothesis. It is important to also consider the limitations and potential sources of error in the study.

5. What is the importance of statistical literacy in scientific research?

Statistical literacy is crucial in scientific research as it allows scientists to make informed decisions based on data and evidence. It also helps in communicating research findings accurately and effectively to other researchers and the general public.

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