What do researchers learn about the normal distribution from knowledge of the standard deviation?
What do researchers learn about the normal distribution from knowledge of the standard deviation?
For the normal distribution, the mean plus and minus one standard deviation will include about what percent of the observations? a. 34% b. 68% c. 48% d. 95%
In a normal distribution, the standard deviation is 20, what test score do you need to be in the top 2.5%? please help no mean is given if there was one i wouldn't ask
The mean of a normal probability distribution is 340; the standard deviation is 12. About 68% of the observations lie between what two values? About 95% of the observations lie between what two values? Practically all of the observations lie between what two values?
The mean of a normal probability distribution is 380; the standard deviation is 16. About 68% of the observations lie between what two values? About 95% of the observations lie between what two values? Practically all of the observations lie between what two values?
The mean of a normal probability distribution is 500; the standard deviation is 14. a. About 68% of the observations lie between what two values? Value 1 Value 2 b. About 95% of the observations lie between what two values? value a Value 1 Value 2 c. Practically all of the observations lie between what two values? Value 1 Value 2
The mean of a normal probability distribution is 400; the standard deviation is 18. a. About 68% of the observations lie between what two values? Value 1 Value 2 L b. About 95% of the observations lie between what two values? Value 1 Value 2 ences c. Practically all of the observations lie between what two values? Value 1 Value 2
Consider a normal distribution with mean 25 and standard
deviation 5. What is the probability a value selected at random
from this distribution is greater than 25? (Round your answer to
two decimal places.)
Assume that x has a normal distribution with the specified
mean and standard deviation. Find the indicated probability. (Round
your answer to four decimal places.)
μ = 14.9; σ = 3.5
P(10 ≤ x ≤ 26) =
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Assume that x has a...
a. Consider a normal distribution with mean 20 and standard deviation 4. What is the probability a value selected at random from this distribution is greater than 20? (Round your answer to two decimal places. b. Assume that x has a normal distribution with the specified mean and standard deviation. Find the indicated probability. (Round your answer to four decimal places.) μ = 14.3; σ = 3.5 P(10 ≤ x ≤ 26) = c. Assume that x has a normal...
24. About what percent of the x values from a normal distribution lie within two standard deviations (left and right) of the mean of that distribution? (Enter an exact number as an integer, fraction, or decimal.) _______ % 25. About what percent of x values lie between the mean and one standard deviation (one sided)? (Enter an exact number as an integer, fraction, or decimal.) _______ % 26. About what percent of x values lie between the first and third standard deviations (both sides)?...
We use a t distribution for inference about a population mean instead of the standard Normal distribution: if we do not know the population mean and must use the sample mean. if the original population does not have a Normal distribution. if we do not have a simple random sample. if we do not know the population standard deviation and must use the sample standard deviation.