"Using Frequency to Estimate Probability" Preliminary Probability PPT Download (Lesson 2)

"Using Frequency to Estimate Probability" Preliminary Probability PPT Download (Lesson 2)

Part One: Learning Objectives

1. Understand the relationship between frequency and probability.

2. Master the use of frequency to estimate the probability of an event occurring.

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1. For general random events, when a large number of repeated tests are performed, as the number of tests increases, the frequency of an event always swings around a fixed number, showing a certain stability. Therefore, we can use the frequency of a random event to estimate its probability through a large number of repeated experiments.

2. What are the differences and connections between frequency and probability?

The frequency changes with the number of trials. Probability is a constant, which is the scientific abstraction of frequency. As the number of trials increases, the average amplitude of the frequency swing around the probability becomes smaller and smaller, that is, the frequency approaches the probability.

Using frequency to estimate probability PPT, part 2: analysis of examples

Example 1 A certain forestry department wants to examine the transplant survival rate of a certain sapling under certain conditions. What specific methods should be adopted? The table on the right is a simulated statistical table. Please fill in the blanks in the table and complete the filling in the blanks.

It can be found from the table that as the number of transplants increases, the frequency of transplanted survival of saplings becomes more and more stable. When the total number of transplants is 14,000, the survival frequency is 0.902, so it can be estimated that the probability of survival of transplanted saplings is ____.

Solution: The survival rate of sapling transplantation is a probability in practical problems. In this problem, it is unknown whether the two results of "survival" and "non-survival" of sapling transplantation are equally likely, so the survival rate must be estimated based on frequency.

Under the same conditions, a large number of such saplings were transplanted, and survival statistics were recorded to calculate the frequency of survival. As the number of transplants n becomes larger and larger, the frequency m/n will become more and more stable, so the frequency can be used as an estimate of the survival rate.

It can be found from the table that as the number of transplants increases, the frequency of transplanted survival of saplings becomes more and more stable. When the total number of transplants is 14,000, the survival frequency is 0.902, so it can be estimated that the probability of survival of transplanted saplings is 0.9.

Using frequency to estimate probability PPT, part 3: practice and consolidation

1. An agricultural science institute conducted a test on the germination rate of seeds of a certain crop under the same conditions. The results are as shown in the table below:

Generally, approximately how many seeds in 1 000 kg cannot germinate?

2. The shooting results of a certain shooter under the same conditions are recorded as follows:

(1) Calculate the corresponding frequency of "shooting more than 9 rings" in the table (retain the result to two decimal places).

(2) How stable are these frequencies?

(3) Based on the stability of the frequency, estimate the probability of "hitting more than 9 rings" when this athlete shoots once (results are retained to one decimal place).

3. Someone contracted to raise fish in a pond, and he wanted to estimate the income. So he asked his son, who was in the third grade of junior high school, to help. His son first asked him to randomly fish out 60 fish from the fish pond, mark each fish and put it back into the fish pond; after two days, his son asked him to fish out 50 fish from the fish pond. , there are 2 marked ones in the result. Assume that the market price of this fish at that time was 2.8 yuan/catty, and the average fish was estimated to be 2.3 catties. Can you help him estimate his income this year?

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For more information about the "Using Frequency to Estimate Probability Preliminary" PPT courseware, please click the Estimating Probability Using Frequency PPT Probability Preliminary PPT tab.

"Using Frequency to Estimate Probability" PPT teaching courseware for further understanding of probability:

"Using Frequency to Estimate Probability" PPT teaching courseware for further understanding of probability, 13 pages in total. Basics of knowledge points Knowledge point 1 The relationship between frequency and probability 1. Regarding the relationship between frequency and probability, the correct statement below is (B) A. Frequency is equal to probability B. When the number of trials is very...

"Using Frequency to Estimate Probability" PPT download for further understanding of probability:

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