Enter mean, standard deviation and cutoff points and this calculator will find the area under normal distribution curve. The calculator will generate a step by step explanation along with the graphic representation of the area you want to find. The default value and shows the standard normal distribution. As explained above, the standard normal distribution table only provides the probability for values less than a positive z-value (i.

Free Online Calculation of Normal Distributions. X mean 0.5-Z X mean 0.5+Z X mean 0.5 Z (X-m) / where, m Mean. Standard Deviation. Calculators for two of the most common situations in probability calculation. To find the probability area P for the normal distribution as well as finding out the confidence intervals table. If 0 and 2 1, it is called standard normal. Since z-scores are for the Standard Normal Distribution, the syntax is normalcdf(smaller z, larger z). Example (TI-83): Find the probability that a z-score is between -1.

Given z score value calculate probability, percentile and area of the standard normal distribution and curve. Normal or Gaussian Distribution Calculator is an online statistics tool for data analysis programmed to calculate the normal probability density function for a given mean and standard deviation. Normal or Gaussian Distribution Calculator is an online statistics tool for data analysis programmed to calculate the normal probability density function for a given mean and standard deviation. Normal Calculator. Select Calculation and enter appropiate value. Calculate probability. Calculate critical value. Critical value. Probability.

### Normal Distribution Calculator

Enter the mean and standard deviation for the distribution. Enter the chosen values of x1 and, if required, x2 then press Calculate to calculate the probability that a value chosen at random from the distribution is greater than or less than x1 or x2, or lies between x1 and x2. Suppose you have a normally distributed random variable and would like to calculate the probability of its value occurring in the interval of the mean plus or minus. The Taylor expansion of the above assists in speeding up the calculation: Standard Normal Probabilities: (The table is based on the area P under the standard normal probability curve, below the respective z-statistic. (The table is based on the area P under the standard normal probability curve, below the respective z-statistic. Find normal distribution probability in Excel with our easy, step-by-step guide. Sample Question: Suppose that a contaminant in samples from a city’s water supply has a mean of 500 ppm and a standard deviation of 100 ppm. The standard normal distribution is centered at zero and the degree to which a given measurement deviates from the mean is given by the standard deviation. In this case, because the mean is zero and the standard deviation is 1, the Z value is the number of standard deviation units away from the mean, and the area is the probability of observing a value less than that particular Z value. However approximate values of these functions can be obtained from the special distribution calculator, and from most mathematics and statistics software.

### Z Score Calculator: Standard Normal Distribution Probability Percentile Area

Use the Normal Distribution Calculator to complete these problems.