Log in 😊 8 years agoPosted 8 years ago. Direct link to 😊's post “how do I calculate the pr...” how do I calculate the probability of a z-score? • (20 votes) Piquan 8 years agoPosted 8 years ago. Direct link to Piquan's post “That's a great question! ...” That's a great question! Fortunately, the next set of lessons, at https://www.khanacademy.org/math/statistics-probability/modeling-distributions-of-data/normal-distributions-library/v/ck12-org-normal-distribution-problems-qualitative-sense-of-normal-distributions , discuss exactly that. It's great that you're thinking ahead! (27 votes) Nick Leshuk 8 years agoPosted 8 years ago. Direct link to Nick Leshuk's post “how do you calculate the ...” how do you calculate the mean when you are only given the z-scores? • (5 votes) RacheLee 8 years agoPosted 8 years ago. Direct link to RacheLee's post “To calculate the mean, yo...” To calculate the mean, you need to know z-scores, the data, and the standard deviation. (14 votes) Tou 6 years agoPosted 6 years ago. Direct link to Tou's post “how do you calculate this...” how do you calculate this: µ=10 and σ =1, P(X>10) • (6 votes) Shaghayegh 4 years agoPosted 4 years ago. Direct link to Shaghayegh's post “Is it necessary to assume...” Is it necessary to assume the distribution is normal? • (3 votes) loumast17 4 years agoPosted 4 years ago. Direct link to loumast17's post “to use z scores. If not,...” to use z scores. If not, or you do not know the population standard deviation you would use a different kind of score called the t score For z scoreyou need both the population standard deviation and for the sample to be greater than 30. There are other aspects in statistics where having a normal distribution is necessary. (7 votes) 1315031658 7 years agoPosted 7 years ago. Direct link to 1315031658's post “How do you find the data ...” How do you find the data when you have the mean, the z-score, and the standard deviation? • (2 votes) Ian Pulizzotto 7 years agoPosted 7 years ago. Direct link to Ian Pulizzotto's post “Let x represent the data ...” Let x represent the data value, mu represent the mean, sigma represent the standard deviation, and z represent the z-score. So the data value equals the z-score times the standard deviation, plus the mean. Have a blessed, wonderful day! (7 votes) sebastian grez 8 years agoPosted 8 years ago. Direct link to sebastian grez's post “what happens when you get...” what happens when you get the number of X-U/standar desviation ahd you get a number above 3, that number will not be in the tabla of Z • (4 votes) psthmn 8 years agoPosted 8 years ago. Direct link to psthmn's post “You could try to find a m...” You could try to find a more extensive Z table, for example here: http://www.intmath.com/counting-probability/z-table.php But at a certain point the difference in probality at changing z values gets vanishingly small, so it doesn't really matter what the actual value at that point is. If you are faced with this situation, in most cases P > P(Z=3) is a useful and sufficient answer. (1 vote) Bryan 4 years agoPosted 4 years ago. Direct link to Bryan's post “Are z-scores only applica...” Are z-scores only applicable for normal distributions? You could describe how many standard deviations far a data point is from the mean for any distribution right? But is the term z-score only for normal dists? • (3 votes) Rebecca 4 years agoPosted 4 years ago. Direct link to Rebecca's post “The z-score could be appl...” The z-score could be applied to any standard distribution or data set. It definition only depends on the (arithmetic) mean and standard deviation, and no other qualitative properties of the nature of the data set. (2 votes) Samael Pena 5 years agoPosted 5 years ago. Direct link to Samael Pena's post “What if I don't have the ...” What if I don't have the score but only the Z score. How can I calculate what the score is • (3 votes) muhammad fajar rizqi 7 years agoPosted 7 years ago. Direct link to muhammad fajar rizqi's post “Hello Everybody, I want t...” Hello Everybody, I want to ask, how to calculate that has z-score is more than 3 or -3? because sometimes i calculate the z-score and can't get the result because it's out of range from the z-table. Thank you • (3 votes) Rosivette Andrade 5 years agoPosted 5 years ago. Direct link to Rosivette Andrade's post “Would anyone mind explain...” Would anyone mind explaining this ? A. about 2 • (2 votes)Want to join the conversation?
z-score=(data-mean)/standard deviation
data-mean=(z-score)(standard deviation)
mean=(data)-(z-score)(standard deviation)
Since the z-score is the number of standard deviations above the mean, z = (x - mu)/sigma.
Solving for the data value, x, gives the formula x = z*sigma + mu.
For a normal distribution of 1000 cases, how many cases will be farther away from the mean than + 3 standard deviations?
B. at least 500
C. it is impossible to estimate
D. 327
FAQs
How do you find z-score formula? ›
How To Calculate. The formula for calculating a z-score is z = (x-μ)/σ, where x is the raw score, μ is the population mean, and σ is the population standard deviation. As the formula shows, the z-score is simply the raw score minus the population mean, divided by the population standard deviation. Figure 2.
How do you calculate the z-score quizlet? ›What is the formula for the z-score? z = x value - mean or mew/ divided by standard deviation or sigma.
How to calculate z-score calculator? ›- Calculate the mean as (∑x) / n .
- Calculate the standard deviation using the easy-to-type formula (∑(x²) - (∑x)²/n) / n . The divisor is modified to n - 1 for sample data.
- Calculate the z-score using the formula z = (x - mean) / standard deviation .
The formula for Altman Z-Score is 1.2*(working capital / total assets) + 1.4*(retained earnings / total assets) + 3.3*(earnings before interest and tax / total assets) + 0.6*(market value of equity / total liabilities) + 1.0*(sales / total assets).
What is the formula for the z-score of a sample size? ›| Formulas for Sample Size (SS) | |
|---|---|
| For Infinite Sample Size | SS = [Z2p (1 − p)]/ C2 |
| For Finite Sample Size | SS/ [1 + {(SS − 1)/Pop}] |
- Determine the mean. The mean, or average, is a value that represents the average value within a data set. ...
- Choose a value for x. ...
- Find the standard deviation. ...
- Perform the calculation.
The z-score is the standard deviation (SD) above or below the mean. A z-score of 0 is at the apex of the curve and is the same as a 50th percentile, a z-score of ± 1.0 plots at the 15th or 85th percentiles, respectively, and a z-score of ± 2 plots at roughly the 3rd or 97th percentiles.
How to calculate z-score and t score? ›To eliminate thesecharacteristics, z scores often are converted to T scores. This isaccomplished using the simple formula: T score = 10(z score) + 50. Forexample, a z score of -2.5 becomes a T score of 25. Therefore, the T scorescale from 20 (-3 SD) to 80 (+3 SD) has a mean of 50 and a SD (standarddeviation) of 10.
What is the formula for z-score percentile? ›Z = (x - mean)/standard deviation. Assuming that the underlying distribution is normal, we can construct a formula to calculate z-score from given percentile T%.
How do you find the z-score of two numbers? ›“Once you have both values, you can easily compute the z-score.” You would use the following formula: Z-score = (the initial data point – mean)/standard deviation.
How is the z-score calculated? ›
How Is Z-Score Calculated? The Z-score is calculated by finding the difference between a data point and the average of the dataset, then dividing that difference by the standard deviation to see how many standard deviations the data point is from the mean.
What is the easiest way to find the z-score? ›There are three variables to consider when calculating a z-score: the raw score (x), the population mean (μ), and the population standard deviation (σ). To get the z-score, subtract the population mean from the raw score and divide the result by the population standard deviation.
What is the z-score for 95 confidence interval? ›The Z value for 95% confidence is Z=1.96.
What is the z-score for 80? ›The Z-score for an 80% confidence interval is approximately 1.28.
How do you calculate the Z factor? ›Z factor is calculated as the separation band divided by the dynamic range (i.e., the difference between the sample mean and the control mean), which is calculated as shown in Equation 1. The same equation can be expressed in Equation 2 when rearranged. Based on Z-factor value, the hits can be discerned.