0
Add your answer:
Earn +20 pts
How do you to get the probability in normal distribution?
You calculate the z-scores and then use published tables.
How do you use the z-score to determine a normal curve?
If the Z-Score corresponds to the standard deviation, then the distribution is "normal", or Gaussian.
When do you use a z - table compared with when you use a t - table?
For statistical tests based on (Student's) t-distribution you use the t-table. This is appropriate for small sample sizes - up to around 30. For larger samples (or degrees of freedom), the t-distribution becomes very close to the Standard Normal distribution so you use the z-tables.
How do you graph normal distribution?
Tables of the cumulative probability distribution of the standard normal distribution (mean = 0, variance = 1) are readily available. Almost all textbooks on statistics will contain one and there are several sources on the net. For each value of z, the table gives Φ(z) = prob(Z < z). The tables usually gives value of z in steps of 0.01 for z ≥ 0. For a particular value of z, the height of the probability density function is approximately 100*[Φ(z+0.01) - Φ(z)]. As mentioned above, the tables give figures for z ≥ 0. For z < 0 you simply use the symmetry of the normal distribution.
What is the normal distribution of 65 seconds and standard deviation 0.8?
If X is Normally distributed with mean 65 seconds and sd = 0.8 seconds, then Z = (X - 65)/0.8 has a Standard Normal distribution; that is, Z has a N(0, 1) distribution. The cumulative distribution for Z is easily available - on the net and in any basiic book on statistics. To get to the cumulative dirtribution function of X all you need is to use the transformation X = 0.8*Z + 65.
When to you use a z scores or t scores?
If the distribution is Gaussian (or Normal) use z-scores. If it is Student's t, then use t-scores.
When to use z or t-distribution?
If the sample size is large (>30) or the population standard deviation is known, we use the z-distribution.If the sample sie is small and the population standard deviation is unknown, we use the t-distribution
How do you to get the probability in normal distribution?
You calculate the z-scores and then use published tables.
How do you use the z-score to determine a normal curve?
If the Z-Score corresponds to the standard deviation, then the distribution is "normal", or Gaussian.
When do you use a z - table compared with when you use a t - table?
For statistical tests based on (Student's) t-distribution you use the t-table. This is appropriate for small sample sizes - up to around 30. For larger samples (or degrees of freedom), the t-distribution becomes very close to the Standard Normal distribution so you use the z-tables.
What is the distribution of absolute values of a random normal variable?
It is the so-called "half-normal distribution." Specifically, let X be a standard normal variate with cumulative distribution function F(z). Then its cumulative distribution function G(z) is given by Prob(|X| < z) = Prob(-z < X < z) = Prob(X < z) - Prob(X < -z) = F(z) - F(-z). Its probability distribution function g(z), z >= 0, therefore equals g(z) = Derivative of (F(z) - F(-z)) = f(z) + f(-z) {by the Chain Rule} = 2f(z) because of the symmetry of f with respect to zero. In other words, the probability distribution function is zero for negative values (they cannot be absolute values of anything) and otherwise is exactly twice the distribution of the standard normal.
What percentage of a normal distribution is located in the tail beyond a z-score of z - 1.20?
11.51% of the distribution.
How do you graph normal distribution?
Tables of the cumulative probability distribution of the standard normal distribution (mean = 0, variance = 1) are readily available. Almost all textbooks on statistics will contain one and there are several sources on the net. For each value of z, the table gives Φ(z) = prob(Z < z). The tables usually gives value of z in steps of 0.01 for z ≥ 0. For a particular value of z, the height of the probability density function is approximately 100*[Φ(z+0.01) - Φ(z)]. As mentioned above, the tables give figures for z ≥ 0. For z < 0 you simply use the symmetry of the normal distribution.
What is the normal distribution of 65 seconds and standard deviation 0.8?
If X is Normally distributed with mean 65 seconds and sd = 0.8 seconds, then Z = (X - 65)/0.8 has a Standard Normal distribution; that is, Z has a N(0, 1) distribution. The cumulative distribution for Z is easily available - on the net and in any basiic book on statistics. To get to the cumulative dirtribution function of X all you need is to use the transformation X = 0.8*Z + 65.
When do you know when to use t-distribution opposed to the z-distribution?
z- statistics is applied under two conditions: 1. when the population standard deviation is known. 2. when the sample size is large. In the absence of the parameter sigma when we use its estimate s, the distribution of z remains no longer normal but changes to t distribution. this modification depends on the degrees of freedom available for the estimation of sigma or standard deviation. hope this will help u.... mona upreti.. :)
What proportion of a normal distribution falls between z 1.16 and z 1.16?
0% of a normal (of any) distribution falls between z 1.16 and z 1.16. 1.16 - 1.16 = 0.
How is the t distribution similar to the standard z distribution?
Z is the standard normal distribution. T is the standard normal distribution revised to reflect the results of sampling. This is the first step in targeted sales developed through distribution trends.
