testing, the GT V textbook presents how to choose the test statistic K and the probability distribution of K , however, different from the statistics in the parametric testing problem, the distribution of K in this case is not known in the topic "Sample Theory".
The following is a summary of the content of section 5.2 in the GT V textbook :
5.2. Hypothesis testing about the mean of a normally distributed random variable Suppose X is a normally distributed random variable N ( ; 2 ) We rely on random samples.
(X 1 , X 2 , …, X n ) to test the hypothesis
1) In case the variance is known2
H 0 : 0 .
( X 0 ) n
Test statistic K
If the null hypothesis H 0 is true, then K has a standard normal distribution N(0; 1).
The problem is divided into 3 cases according to the pair of hypotheses H 0 , H 1 :
a) Hypothesis testing
H 0 : 0 with the alternative hypothesis
H 1 : 0 …
b ) Hypothesis testing
c) Hypothesis testing
H 0 : 0 with the alternative hypothesis
H 0 : 0 with the alternative hypothesis
H 1 : 0 …
H 1 : 0 …
Example 5.1. According to the contract between the supplier…
2) In case the variance is not known2
Test statistics
K ( X
0 ) n S
If the hypothesis H 0 is true, then K has a Student distribution with degrees of freedom df = n – 1. The problem is divided into 3 cases according to the hypothesis pair H 0 , H 1 :
a) Hypothesis testing
H 0 : 0 with the alternative hypothesis
H 1 : 0 …
b ) Hypothesis testing
c) Hypothesis testing
H 0 : 0 with the alternative hypothesis
H 0 : 0 with the alternative hypothesis
H 1 : 0 …
H 1 : 0 …
Example 5.2. A medical report states that the average hemoglobin level for Vietnamese people is 138 (g/l). Measuring the hemoglobin of 25 factory workers exposed to chemicals, the sample mean was calculated to be 123.7 (g/l), the sample standard deviation was 13.2 (g/l). From this survey result, there is a basis to say that the average hemoglobin of the workers
factory workers is lower than the average of Vietnamese people or not, at the significance level of 0.05. Suppose the hemoglobin of factory workers is a random variable satisfying normal distribution.
Example 5.3. Use SPSS statistical software to test the hypothesis about the mean of the population... [GT V , pp.115-118].
The above quote shows that, for the task type T 1μ, the hypothesis test about
The mean of a normally distributed random variable , the GT V textbook presents techniques for solving this type of task implicitly. Based on the general presentation of statistical hypothesis testing rules, the GT V textbook shows how to choose K , how to determine W suitable for each case.
We call:
- The Z test is a test in which the test statistic K is chosen to have a standard normal distribution N (0; 1). Similarly,
- The t -test is a test in which K has a Student distribution.
- The F test is a test in which K has a Fisher distribution.
- Test method
2 is the test that K has a Chi square distribution
2 .
- The Z- approximation test is the K- test with approximately normal distribution N (0; 1).
The problem of testing statistical hypotheses related to the parameters of random variables is divided into 3 cases according to the pair of hypotheses H 0 , H 1 , in which we call:
- “Hypothesis testing
Justify .
- “Right -sided hypothesis testing .
- “Hypothesis testing
left
H 0 : 0 with the alternative hypothesis
H 0 : 0 with the alternative hypothesis
H 0 : 0 with the alternative hypothesis
H 1 : 0 ” is the test
H 1 : 0 ” is the test
H 1 : 0 ” is the test
1
Symbol ZL is a technique for testing a mean using the Z-test.
left , that is how to solve the problem of testing the hypothesis about the average of a random variable
normal distribution in the case of unknown variance
2 , fake test
theory
H 0 : 0
with alternative hypothesis
H 1 : 0 ”, select test statistic
K ( X 0 )
n
S
has a standard normal distribution N (0 ; 1). We have ZL
1
is a technique to solve
decide the task type T 1μ .
b) About examples and exercises
The GT V textbook has included a number of practical medical problems, using data related to hemoglobin, blood pressure, glucose content of patients, weight of newborns, disintegration time of a drug, nitrogen quantification, sleep time of drugs, weight of powdered drug packages, blood group distribution, pulse rate, IQ. For statistical hypothesis testing related to parameters of random variables, the GT V textbook provides 14 examples, from example 5.1 to example 5.14, illustrating each testing problem, of which 4 examples require solving the testing problem by exploiting the application of SPSS statistical software, which are examples 5.3, 5.9, 5.10b,
5.14. In the exercises section of the GT V textbook , there are 9 exercises on this topic, including exercises 1 to 9. Similarly, for statistical hypothesis testing of conformity, the GT V textbook provides 6 examples, from example 5.15 to example 5.20, and there are 6 exercises on this topic, including exercises 10 to 15. In the examples, the techniques for solving various types of tasks are illustrated in detail. Consider example 5.2 in the GT V textbook below:
“Example 5.2. A medical report states that the average hemoglobin level for Vietnamese people is 138 (g/l). Measuring the hemoglobin of 25 factory workers exposed to chemicals, the sample mean is 123.7 (g/l), the sample standard deviation is 13.2 (g/l). From this survey result, is there a basis to say that the average hemoglobin of factory workers is lower than the average of Vietnamese people, with a significance level of 0.05. Suppose that the hemoglobin of factory workers is a random variable that satisfies the normal distribution.
Solution: Let X be the amount of hemoglobin of chemical factory workers, X N ( ; 2 ) . Problem of testing hypothesis about the mean of a normally distributed random variable in case the variance is unknown.
Hypothesis testing
H 0 : 138 (g/l) with alternative hypothesis
H 1 : 138 (g/l).
Test statistics
K . If hypothesis H
right then
( X 138) n
S0
K ( X
)n
0.05
S
has a Student distribution with degrees of freedom df = n – 1 = 24.
With = 0.05, region of rejection of the hypothesis
W ( ; t 24
) ( ; 1, 711) .
From the survey sample data n = 25, we have
K 0 5, 417 .
(123, 7 138) 25
13, 2
K 0 W There should be a basis to reject the hypothesis H 0 and accept H 1 .
From this it can be assumed that the average hemoglobin of chemical factory workers is lower than the national average” [GT V , pp.117-118].
1
1
Example 5.2 illustrates the technique.tL solves a task type T 1μ , where tL
is a left-tailed t-test, used to test whether the mean of a random variable satisfies a normal distribution, the population variance is unknown, the test statistic K is chosen to have a Student distribution.
On the technique of solving different types of tasks T
; T ; T ; T
; T pair ; T ;
1 μ 1 p
1 2
2 μ 2
2 p 2 2
T Anova ; T phuhop ; T doclap , we summarize in Table 3.3, Table 3.4 and Table 3.5.
2 2
Table 3.3. Corresponding techniques for task types T 1 μ , T 1 p , T 1 2
Task type
Technique | |
T 1 μ | ZJ two-tailed Z test 1 |
ZR right-tailed Z-test 1 | |
ZL two-tailed Z test 1 | |
tJ two-tailed t-test 1 | |
tR right-tailed t-test 1 | |
tL left-tailed t-test 1 | |
T 1 p | ZJ two-tailed Z-test approximation 1 p |
ZR right-sided Z-test approximation 1 p | |
ZL left-sided Z-test approximation 1 p | |
T 2 1 | 2 J two-tailed 2 test 1 2 |
2R test 2right side 1 2 | |
2 L left -tailed test 1 2 |
Maybe you are interested!
-
Improving the efficiency of raw material import activities at C&T Construction and Materials Trading Joint Stock Company - 2 -
Practice Exercise 2: Welding “T” Corner Without Chamfer 2 Carbon Steel Plates Using Gmaw Welding Method At 3F Position (S=10Mm) -
T-Bevel Welding Technique Without Bevel Position: -
Measuring the Period (T) and Frequency (F) of a Signal: Order to Calculate the Period, Frequency of a Signal Step 1. Read the Time/div Number. -
Phylogenetic Tree of Nucleotide Sequence of Gen M of CC Strain IA/h5N1 Clade 7 (Established by Neighbo-Joining Analysis Using Mega 5 Software, Gi T

Table 3.4. Corresponding techniques for task type T
, T pair , T , T , T
2 μ 2 2 p 2 2
Anova
Task type
Technique | |
T 2 μ | ZJ two-tailed Z test 2 |
ZR right-tailed Z-test 2 | |
ZL two-tailed Z test 2 | |
tJ 1 case t-test 2 2 , two sides 2 1 2 | |
tR 1 t-test for case 2 2 , right side 2 1 2 | |
tL 1 case t-test 2 2 , left side 2 1 2 | |
tJ 2 case t-test 2 2 , two sides 2 1 2 | |
tR 2 t-test for case 2 2 , right side 2 1 2 | |
tL 2 case t-test 2 2 , left side 2 1 2 | |
ZJ is the approximate Z test for the case where sample n 1 > 30, 2 n 2 > 30, two sides | |
ZR is the approximate Z test for the case where n 1 > 30 samples, 2 n 2 > 30, right side | |
ZL is the approximate Z test for the case where sample n 1 > 30, 2 n 2 > 30, left side | |
T pair 2 | tJ pair two-tailed t-test 2 |
T 2 p | ZJ two-tailed Z-test approximation 2 p |
ZR right-sided Z-test approximation 2 p | |
ZL left-sided Z-test approximation 2 p | |
T 2 2 | FJ two-tailed F test 2 2 |
FR right-tailed F-test 2 2 | |
T Anova | One-way analysis of variance (Anova) |
Table 3.5. Corresponding techniques for task types T phuhop , T doclap
2 2
Task type
Technique | |
T phuhop 2 Testing the hypothesis of conformity | conformity testing 2 (condition n > 50, n i >= 5) |
T doc 2 Testing the hypothesis of independence of two qualitative variables | doclap test of independence of 2 two qualitative variables (condition E i >= 5) |
The technological factors that explain the respective techniques for solving these 10 types of tasks include:
- Rules of inference of statistical hypothesis testing.
- Theories to support each step of the inference of the tests
is chosen as Z , t , F or test2
indicated in each technique.
- Theory of validity when using tests: for parametric tests, the conditions to be checked are whether the random variable must satisfy the normal distribution, the variance is known or unknown, the variances are homogeneous or not,
large or small sample size; for tests
2 , the condition to be checked is sample size,
Experimental frequency, expected frequency large or small.
Thus, compared to the proposed set of task types , the GT V textbook has mentioned low-level task types, tending towards calculation, applying processes and procedures.
statistical hypothesis testing T
, T , T
, T , T pair , T , T , T
, T phuhop , T doclap ,
1 μ 1 p
1 2
2 μ 2
2 p 2 2
Anova 2 2
For the type of mission that requires SLTKYH at a higher level than T kdgt , T kdgt then GT V has not been
Gkl UNcyh
mentioned, although it has included practical medical problems that require the use of SPSS statistics to process data.
3.3.2.4. Topic “Regression and Correlation Analysis” in GT V textbook
This topic is presented in chapter 6 of GT V textbook including the following contents: Chapter 6. Regression and correlation analysis
6.1. Regression analysis
6.2. Regression model fit
6.3. Correlation analysis
6.4. Regression and correlation analysis in SPSS
a) In theory
When several random variables are studied simultaneously, the question arises whether these variables are related or independent. In the case of a relationship, it is necessary to determine the degree of the relationship and, if possible, to represent the relationship using mathematical expressions. In medical research, people are often interested in assessing the relationship between quantitative variables, for example the relationship between blood pressure and age, weight and height, drug concentration and heart rate.
Regression and correlation analysis presents methods for analyzing that relationship according to three issues:
- Determine whether or not there is a relationship between two variables by testing the hypothesis of statistical independence.
- Assess the degree of association between two variables based on the concept of correlation coefficient.
- Describe this relationship in a mathematical form called a regression function [GT V , p.153].
GT V textbook presents univariate regression analysis, which is a method of analyzing the relationship between two variables: the response variable, also known as the dependent variable, and the explanatory variable, also known as the independent variable. The explanatory variable is not random, the response variable has countless factors affecting it, it is a random variable. GT V textbook only presents the univariate linear regression model and how to estimate the regression model using the sample regression function.
With the task type
1
T
HqTq
establish a sample regression function, section 6.5.1 estimates the parameters
The GT V textbook regression number presented one technique for solving that type of task, the second technique is presented in comment 6.1 of the textbook. For this type of task
T
service
2
HqTq
, GT V refers to the theory presented in section 6.2 of GT V , however
There are no illustrative examples. The GT V textbook has presented techniques for solving the problems.
T 3 and T 4 task types are implicitly presented in the theory and illustration section.
HqTq HqTq
through examples, however, not complete. Section 6.3 Correlation analysis, GT V textbook presents the definition of Pearson correlation coefficient, but does not state the standard conditions of two random variables X , Y , and does not present the correlation testing procedure based on sample data.
b) About examples and exercises
The GT V textbook has included a number of practical medical problems, using data related to studies on the relationship between the remaining life span and the dose of poison injected into the body, between the dose of Methadone and the QTc interval of the electrocardiogram, between the number of bacteria reproduced and time, between the increase in the dose of sedatives and the time of sleep, between the time for the drug to completely decompose in the body and the age of the patient. The GT V textbook has provided 6 examples from example 6.1 to example 6.6, in which examples 6.1, 6.2 and 6.5b illustrate the use of one of the two techniques.
HqTq
techniques for solving task type T 1 . Examples 6.3, 6.4 and 6.5a relate to techniques
solve the task type
3
T
HqTq
. Related to task type solving techniques
HqTq
T 4 , GT V textbook gives example 6.5b, however, it is only at the level of calculating sample regression coefficients using statistical procedures in CASIO pocket calculator or SPSS statistical software, from the sample regression function calculating the predicted value of the variable
Conclusion. GT V textbook gives example 6.6 to illustrate the technique of solving this type of problem.
Tasks T1 and T3 using SPSS statistical software, also just at
HqTq HqTq
level of presenting some operations performed on SPSS and reading some results of calculating correlation coefficients, regression coefficients and sample regression functions. GT V textbook does not give examples
Which illustrates the task-type solving technique?
2
T
HqTq
. GT V textbook offers 3
Exercises related to task types T 1 , T 3 , T 4 similar to example 6.5.
HqTq HqTq HqTq
Thus, compared with the proposed set of task types , the GT V textbook has taken into account
all 4 types of tasks T 1 , T 2 , T 3 , T 4 , however only mentioned the case
HqTq HqTq HqTq HqTq
examining the relationship between two variables, not to mention the case of examining the relationship between multiple variables. The requirements for solving these types of tasks are also limited to performing calculations, applying familiar formulas and algorithms, not taking into account SLTKYH at a higher level. Although practical medical problems have been included in which the use of SPSS statistics is required to process data, the task of applying regression and correlation analysis methods in practical problem solving in medical research has not been mentioned, making well-founded predictions, these predictions are used in diagnosing, preventing diseases or evaluating the effectiveness of treatment methods.





