A negative z score always indicates that the raw score is below the mean?
Yes, it does.
Vale verga ;)
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In general, the answer is no, both negative and positive z score values should be expected.. A z-score (or standardize score) is the raw data value minus the mean and then th…is result divided by the standard deviation. If the data can be considered normally distributed and a random sample is taken from a population, then as the sample size becomes large, approximately half the z-scores should be negative and half of the z-scores should be positive.. There are some exceptions. Small data sets may have only positive values. A non-normal (skewed) distribution if skewed to the right, may have, after normalizing, may have a higher portion of z scores as positives.
Let your raw score be x and M the mean and S the standard deviation. The Z score for your specific x is Z=(x-M)/S So say your score is 80 (out of 100) and the mean is 70 a…nd the standard deviation is 10. Then the z score for your 80 is: (80-70)/10=1 If on the other hand you got a 60, then the z score would be -1.
A negative z score is a value that is less than the mean value.
It means that it is less than the mean.
A z-score requires the mean and standard deviation (or standard error). There is, therefore, not enough information to answer the question.
Without more information you cannot.
The one-tailed z-value is: P(Z < z) = 0.9693 => z = 1.8706
Yes. However, because the distribution is symmetric about 0, some tables give only positive values for z.
It means that your raw score is four standard deviations below the mean. This will mean different things depending on the context of the question. If you're looking at the pro…bability of a single score occurring in a given distribution (say, a score of 40 in a distribution of scores with a mean of 80 and a std. dev. of 10), then this means that the probability of getting a 40 is very, very low--less than .00002.
z = (x - Î¼) / Ï is the formula where x is the raw score and z is the z-score. Î¼ and Ï are the mean and standard deviations and must be known numbers. Multiply b…oth sides by Ï zÏ = x-Î¼ Add Î¼ to both sides Î¼ + zÏ = x x = Î¼ + zÏ You calculate the raw score x , given the z-score, Î¼ and Ï by using the above formula.
Yes. The z or Standard Normal distribution is symmetric about the value z = 0.
z-score of a value=(that value minus the mean)/(standarddeviation). So if a value has a negative z-score, then it is belowthe mean.
There is not enough information to answer your question. To determine a Z-Score, the mean and standard deviation are also required.
A percentile is always between 0% and 100%, never negative.