0
How do you find the number z such that 93 percent of all observations from a standard Normal distribution are greater than z?
The tables for Z-scores are given in the form of P = Prob(Z < z) for various value of P and z.
Since Prob(Z > z) = 0.93 > 0.5, then by symmetry, z < 0.
So suppose z = -a where a > 0
Now Prob(Z > -a) = 0.93 is the same as Prob(Z < a) = 0.93 [because the standard Normal is symmetric].
therefore, from the tables, a = 1.4758 (approx)
and so z = -1.4758 (approx).
Add your answer:
Earn +20 pts
How many standard deviations are 95 percent of measurements away from the mean?
95 percent of measurements are less than 2 standard deviations away from the mean, assuming a normal distribution.
What is the z-values associated with the middle 44 percent of the standard normal distribution?
-0.772 < Z < 0.772
What percent of the data in a normal distribution lies more than 2 standard deviations above the mean?
2.275 %
Which is a greater discount 25 percent or 70 percent?
70 percent is the greater discount.
Which is greater 35 percent percent 60 or 30 percent percent 80?
35% of 60 is the greater amount.
What percent of observations are above the third quartile in a distribution?
25 percent
What percent of the observations in a distribution lie between the first quartile and the third quartile?
50%
How do you find the population mean for a 95 percent confidence interval?
It depends whether or not the observations are independent and on the distribution of the variable that is being measured or the sample size. You cannot simply assume that the observations are independent and that the distribution is Gaussian (Normal).
What percent of the scores in a normal distribution will fall within one standard deviation?
It is 68.3%
In a standard normal distribution 95 percent of the data is within plus standard deviations of the mean?
95% is within 2 standard deviations of the mean.
In a standard normal distribution about percent of the scores fall above a z-score of 3.00?
0.13
The standard z-score such that 80 percent of the distribution is below to the left of this value is?
z = 0.8416
How many standard deviations is needed to capture 75 percent of data?
It depends on the shape of the distribution. For standard normal distribution, a two tailed range would be from -1.15 sd to + 1.15 sd.
How many standard deviations are 95 percent of measurements away from the mean?
95 percent of measurements are less than 2 standard deviations away from the mean, assuming a normal distribution.
Is the middle spread that is the middle 50 percent of the normal distribution is equal to one standard deviation?
false
What is the z-values associated with the middle 44 percent of the standard normal distribution?
-0.772 < Z < 0.772
What percent of the data in a normal distribution lies more than 2 standard deviations above the mean?
2.275 %
