139k views
4 votes
For a population with μ = 65 and σ = 4, what is the x value corresponding to z = -2.25?

User Roughnecks
by
8.0k points

1 Answer

0 votes

Final Answer:

The x value corresponding to z = -2.25 for a population with mean (μ) = 65 and standard deviation (σ) = 4 is x = 55. The x value is calculated using the formula x = μ + (z × σ), where μ represents the mean, z denotes the z-score, and σ is the standard deviation.

Step-by-step explanation:

In statistics, the z-score represents the number of standard deviations a particular data point is from the mean of a distribution. The formula to calculate the x value from a z-score is x = μ + (z × σ), where x is the data point, μ is the mean, z is the z-score, and σ is the standard deviation.

Given that the population has a mean (μ) of 65 and a standard deviation (σ) of 4, and the z-score (z) is -2.25, substituting these values into the formula gives x = 65 + (-2.25 × 4) = 65 - 9 = 55. This means that a data point located 2.25 standard deviations below the mean in this distribution corresponds to an x value of 55.

Therefore, an x value of 55 corresponds to a z-score of -2.25 in this population. It indicates that a data point with a value of 55 is 2.25 standard deviations below the mean of 65 in this particular distribution. This method allows for the translation between z-scores and actual data values within a normal distribution, aiding in statistical analysis and interpretation of data.

User Igelr
by
8.5k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.