This CDF calculator computes the cumulative probability P(μ-x <= X <= μ+x) for a given normal distribution and also offers features including inverse CDF calculations, and solving for the mean (μ) and standard deviation (σ). It can also create a plot as a function of any of the paramaters.
Determine the likelihood that the actual revenue will closely align with the forecasted figure, falling within a $0.5 million range above or below the $10 million forecast, with historical deviations suggesting a standard deviation of $1 million.. This analysis will help gauge the forecast's reliability, supporting more informed business decisions and strategic adjustments as needed.
Value | Keystrokes | Display | Description |
---|---|---|---|
.5 | x | 0.500 | Stores the x value. |
10 | μ | 10.0 | Stores the μ (mean) value. |
1 | σ | 1.00 | Stores the σ (standard deviation) value. |
P(μ±x) | 0.383 | Calculates the CDF P(μ-x≤X≤μ+x). |
Normal Distribution CDF 2 Tails 0.500 : The x value. 10.0 : The mean of the distribution. 1.00 : The standard deviation of the distribution. 0.383 : The normal CDF, 2 tail P(μ-x≤X≤μ+x). Result: 0.383
What is the value of x for a cdf of 0.8?
These keystrokes assume the values from example 1.
Value | Keystrokes | Display | Description |
---|---|---|---|
.8 | P(μ±x) | 0.800 | Stores the cdf value. |
x | 1.28 | Calculates the x value. |
Normal Distribution CDF 2 Tails Solving for x, x value, with initial value (guess) of 0.500 1.28 : The x value. 10.0 : The mean of the distribution. 1.00 : The standard deviation of the distribution. 0.800 : The normal CDF, 2 tail P(μ-x≤X≤μ+x). Result: 1.28
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