Step-by-step explanation: This simple confidence interval calculator uses a Z statistic and sample mean (M) to generate an interval estimate of a population mean (μ).

Note: You should only use this calculator if (a) your sample size is 30 or greater; and/or (b) you know the population standard deviation (σ), and use this instead of your sample's standard deviation (an unusual situation). If your data does not meet these requirements, consider using the t statistic to generate a confidence interval.

where:

M = sample mean

Z = Z statistic determined by confidence level

sM = standard error = √(s2/n)

As you can see, to perform this calculation you need to know your sample mean, the number of items in your sample, and your sample's standard deviation (or population's standard deviation if your sample size is smaller than 30). (If you need to calculate mean and standard deviation from a set of raw scores, you can do so using our descriptive statistics tools.)

6 0

3 years ago

Lin is playing hand ball and wants the ball to bounce off wall CB and land at D. Where on the wall should she aim if she's stand

ASHA 777 [7]

The triangles formed by the path of the ball and the wall in the given diagram are similar triangles.

<h3>Correct Response;</h3>

The point on the wall she should aim is; <u>A. 7.8 feet away from point B</u>

<h3 /><h3>Method by which the above value is obtained;</h3>

The possible diagram in the question is attached

Let <em>x</em> represent the distance from point <em>B</em> where the ball lands.

ΔCDE is similar to ΔABE, by Angle-Angle similarity postulate.

By trigonometric ratio, the tangent of the angles ∠CDE and ∠BAE are;