Final answer:
The notation Zα refers to the z score with an area of α to its left. The z score measures how many standard deviations a certain value is above or below the mean. The correct point is • to its left.
Step-by-step explanation:
The notation Zα refers to the z score with an area of α to its left.
The z score measures how many standard deviations a certain value is above or below the mean. When the z score is positive, the value is above the mean, and when it is negative, the value is below the mean.
For example, if we have a standard normal distribution, Z ~ N(0, 1), and we want to find the z score that corresponds to an area of 0.9 to the left of it, we can use a z-table to find that the z score is approximately 1.28.
The notation Zα refers to the z-score on the standard normal distribution, which has a specific area to its left, between itself and the mean, or to its right, depending on context.
The z-score reflects how many standard deviations a value x is from the mean (μ). For example, if one is looking for Z0.025, this would indicate the z-score that has an area of 0.025 to its right under the normal curve. Consequently, the area to the left would be 1 - 0.025 = 0.975.