Math Problem Statement

Normaalijakauman N(μ, σ²) nyrkkisääntöjen soveltaminen. Tarkastellaan normaalijakaumaa N(136; 3²). Todennäköisyydet eri väleille ja arvoille, kuten 68.3%, 95.4%, 99.7%, 50%, ja 0%.

Solution

The image shows a problem involving a normal distribution N(μ,σ2)N(\mu, \sigma^2) with mean μ=136\mu = 136 and variance σ2=9\sigma^2 = 9 (hence standard deviation σ=3\sigma = 3). It asks to match the given probability statements to specific values based on standard properties of the normal distribution:

  1. 68.3% of values lie within μ±σ\mu \pm \sigma:

    • This means between 1363=133136 - 3 = 133 and 136+3=139136 + 3 = 139.
    • Corresponding probability: 68.3% for the interval 133, 139.
  2. 95.4% of values lie within μ±2σ\mu \pm 2\sigma:

    • This means between 1366=130136 - 6 = 130 and 136+6=142136 + 6 = 142.
    • Corresponding probability: 95.4% for the interval 130, 142.
  3. 99.7% of values lie within μ±3σ\mu \pm 3\sigma:

    • This means between 1369=127136 - 9 = 127 and 136+9=145136 + 9 = 145.
    • Corresponding probability: 99.7% for the interval 127, 145.

Additional statements:

  1. Probability of a value being greater than 136:

    • For a normal distribution, the probability is exactly 50% since 136 is the mean.
  2. Probability of a value being less than 136:

    • Same as above, the probability is 50%.
  3. Probability of a value being exactly 136:

    • For a continuous distribution, the probability of taking any exact value is 0%.

Summary:

  • Greater than 136: 50%
  • Less than 136: 50%
  • Exactly 136: 0%

Would you like more details or have any other questions?

Related Questions:

  1. What are the properties of the standard normal distribution?
  2. How do we calculate probabilities for non-standard intervals in a normal distribution?
  3. What is the empirical rule and how does it apply to normal distributions?
  4. How do you calculate z-scores and their corresponding probabilities?
  5. How can the normal distribution be used in hypothesis testing?

Tip:

For normally distributed data, about 68%, 95%, and 99.7% of values lie within 1, 2, and 3 standard deviations from the mean, respectively. This is known as the Empirical Rule or the 68-95-99.7 rule.

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Math Problem Analysis

Mathematical Concepts

Probability
Normal Distribution
Empirical Rule

Formulas

μ ± σ
μ ± 2σ
μ ± 3σ

Theorems

Empirical Rule (68-95-99.7 rule)
Properties of Normal Distribution

Suitable Grade Level

Grades 10-12