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The probability of success in one thing is 1%, what is the probability of success in 100 times
This problem is a mathematical probability problem. If we succeed 100 times, the probability is 1% to the 100th power. The 63% downstairs should be the probability of at least one success in 100 times. This truth is that we must persevere, and the probability of success will be greater and greater
Given the mean and standard deviation of two groups of data, can we find their total mean and standard deviation?
For example: given that the average value of group a data is m, the standard deviation is n, the average value of group B data is p, and the standard deviation is Q, find the average value and standard deviation of a + B
No, we also need to know the number of values in each group of data
The average value of the normal distribution of the height of a group of students is 165cm, and the standard deviation is 16cm
Given n (to the second power of 205,20), find the probability of P (x is less than or equal to 230)
2. Give that X &; n (205,20 Square). Find the probability that P (x is less than or equal to 230)
Direct standardization 230-205 divided by 20 results in 1.25, and P is 0.8944 by looking up the table. Similarly, 170-165 divided by 16 results in 0.3125, and P is 0.3764 by looking up the table
What is the formula for Newton's second law?
The common form of Newton's law is: F = ma
The formal form is: F = D (MV) / dt
If f = MDV / dt = ma
This is the general formula of Newton's second law, that is, the differential formula
What determines the type of elements? What is the type of elements?
The number of protons determines the type of element
Proton number = atomic number
Why is the expression of Newton's second law f = ma only in the international system of units
F = KMA when m is 1 mg and a is 0.1 km / S2, isn't k also 1? Isn't f also equal to ma?
What determines the kind of atom?
It is ()
A proton number, B neutron number, C electron number, D relative atomic mass
A the number of protons determines the number of electrons outside the nucleus and the chemical properties of the atom
The number of protons and B neutrons together determine the mass of the atom
Generally, the number of protons and B neutrons are equal
Expression of Newton's second law
High school physics
F = ma, when the resultant force is decomposed on the mutually perpendicular x-axis and y-axis, its expression is: FX = max, FY = may
What kind of atom determines the element
Protons;
The different atomic particles that determine the same element are neutrons. Such particles are called isotopes, such as protium, deuterium and tritium. They all have one proton in their nuclei, but they have 0 neutrons, 1 neutrons and 2 neutrons in their nuclei respectively
The formula of Newton's second law?
1. Newton's second law formula: the acceleration of the object is directly proportional to the combined external force F, inversely proportional to the mass of the object, and the direction of acceleration is the same as that of the combined external force
2. The formula is: F = ma
3. The application scope of Newton's second law
(1) It is only suitable for objects moving at low speed
(2) Newton's second law does not apply to microscopic atoms
(3) The reference frame should be inertial
RELATED INFORMATIONS
- 1. There are two groups of data. The average value of the first group is larger than that of the second group. Is the standard deviation of the first group larger than that of the second group? Must it be big?
- 2. What is the point estimate of the sample standard deviation? A question mentioned in the senior three exam, as mentioned above, people who know it tell me, Sheila
- 3. Must the standard deviation be less than the average
- 4. What is the standard deviation in mathematics?
- 5. The standard deviation of a set of data 13, 14, 15, 16, 17 is () A. 0B. 10C. 2D. 2
- 6. Independent repeated experiment and binomial distribution Is the independent repeated experiment a kind of binomial distribution? If not, what is the difference between them?
- 7. 1. The edge length of cube abcd-a'b'c'd 'is 1. If e is the midpoint of DD', then the distance from B 'to plane Abe is \. 2. In the xoy rectangular coordinate system, it is known that a (4,0), B (0,4), the light ray emitted from point P (2,0) is reflected by the straight line AB, then it is reflected by the straight line ob, and then it is returned to point P, then the path of the light ray is \. 3. Let a, B and C be unit vectors, and a · B = 0, then the minimum value of (A-C) · (B-C) is uuuuuuuuuuuuuuuuuuuuuuuuuu. 4. If the function f (x) defined on R belongs to R for any X1 and X2, f (x1 + x2) = f (x1) + F (x2) - 1 holds, and if x > 0, f (x) > 1. 1) It is proved that f (x) - 1 is an odd function; 2) It is proved that f (x) is an increasing function on R; 3) If f (4) = 5, solve the inequality f (3m ^ 2-m-2)
- 8. It is found that one m-bacteria can self replicate while killing the virus. It is known that one m-bacteria can kill a virus and split into two m-bacteria. What is the maximum number of m-bacteria that can be produced by one m-bacteria and 2047 viruses_______ My answer is 2 * 2047 = 4094. What's wrong,
- 9. High school mathematics combination C 6 superscript 10 subscript is how many how to calculate
- 10. In word, how to use superscript and subscript at the same time and make them aligned. The most important is the latter
- 11. There are two children in a family, one of whom is known to be a girl, and the probability that the other child is also a girl is? (the probability that each child is a boy is equal to that of a girl) Our teacher talked about four basic events: male, male, female, male and female. Then there are three other events except "male", so it is 1 / 3 But I think men and women, as well as women and men, belong to the same basic event. It should be one half,
- 12. Given that a family has three children, and one of them is a girl, what is the probability of having at least one boy? List analysis method The total number of male and female distribution list of 3 children is the third power of 2, which is 8. Why do we consider 8 kinds of children? Why are there differences between male and female! The answer is 6 / 7, which is the birth probability of several children. One of them is female, so there is no male list 1 male and female 2 women and men 3 men and women 4 women and men 5 women 6 men and women 7 women and men Because one of them was a girl and came to seven conclusions, and six of them were boys So it's 6 / 7 Why do you think about eight, men and women and men and women
- 13. In each test, the probability of occurrence of event a is p, and the probability of occurrence of odd times of event a in n independent tests is calculated
- 14. (both words and symbols are required!)
- 15. The symbolic expression and reaction phenomenon of the chemical reaction of carbon dioxide into clarified lime water are obtained
- 16. What is the symbolic expression for testing the chemical reaction of carbon dioxide with clarified lime water
- 17. Triangle sign in chemical reaction expression Is it OK to write the triangle below or above the arrow Still have chemical property, lively is inert
- 18. Can you tell me about the difference and calculation of currency depreciation rate and inflation rate? For example, the original ratio of RMB to us dollar was 8:1. Later, the exchange rate of RMB to us dollar depreciated by 20%. How should the formula be listed? If it is an appreciation of 20%, and if it is an appreciation or depreciation of US dollar to RMB, how should the formula be calculated? The reward can be added
- 19. Is inflation the same as currency depreciation
- 20. 40 years later, meisuizi and her family came to see general Nie. There were 100 words