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IQ scores are normally distributed with a mean of 100 and a standard deviation of 15 If a certain statistician has an IQ of 140 what percent of the population has an IQ less than she does?
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∙ 8y ago
99.6% for
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∙ 8y ago
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What percentage of the normally distributed population lies within the plus or minus one standard deviation of the population mean?
68.2%
True or false a distribution of sample means is normally distributed with a mean equal to the population mean and standard deviation equal to the standard error of the mean?
True.
Does a population have to be normally distributed in order to use the chi-square distribution?
No, but the approximation is better for normally distributed variables.
A particular fruit's weights are normally distributed, with a mean of 298 grams and a standard deviation of 13 grams.If you pick one fruit at random, what is the probability that it will weigh between 262 grams and 269 grams?
A particular fruit's weights are normally distributed, with a mean of 760 grams and a standard deviation of 15 grams. If you pick one fruit at random, what is the probability that it will weigh between 722 grams and 746 grams-----A particular fruit's weights are normally distributed, with a mean of 567 grams and a standard deviation of 25 grams.
Mrssung gave a test in her trigonometry class the scores were normally distributed with a mean of 85 and a standard deviation of 3 what percent would you expect to score between 82 and 88?
67% as it's +/- one standard deviation from the mean
IQ scores are normally distributed with a mean of 100 and a standard deviation of 15 if a certain statistician has an IQ of 140 what percent of the population has an IQ less than he does?
About 98% of the population.
What percentage of the normally distributed population lies within the plus or minus one standard deviation of the population mean?
68.2%
When the population is normally distributed population standard deviation s is unknown and the sample size is n equals 15 the confidence interval for the population mean s is based on the?
The Z test.
What are the best statistics to use for data that is normally distributed?
The mean and standard deviation. If the data really are normally distributed, all other statistics are redundant.
True or false a distribution of sample means is normally distributed with a mean equal to the population mean and standard deviation equal to the standard error of the mean?
True.
Does a population have to be normally distributed in order to use the chi-square distribution?
No, but the approximation is better for normally distributed variables.
What will the sampling distribution of the mean be if a population is normally distribution?
Also normally distributed.
A particular fruit's weights are normally distributed, with a mean of 298 grams and a standard deviation of 13 grams.If you pick one fruit at random, what is the probability that it will weigh between 262 grams and 269 grams?
A particular fruit's weights are normally distributed, with a mean of 760 grams and a standard deviation of 15 grams. If you pick one fruit at random, what is the probability that it will weigh between 722 grams and 746 grams-----A particular fruit's weights are normally distributed, with a mean of 567 grams and a standard deviation of 25 grams.
In the population SAT-Math scores are normally distributed with a mean of 500 and standard deviation of 100?
The answer depends on what SAT tests. In the UK the mean is 100 and the SD approx 15 - the scores are truncated at 100 +/- 44.
Lets assume you have taken 100 samples of size 36 each from a normally distributed population Calculate the standard deviation of the sample means if the populations variance is 25?
square (25/36) = 5/6 = .833
Why is the central limit theorem an important idea for dealing with a population not normally distributed?
According to the Central Limit Theorem, even if a variable has an underlying distribution which is not Normal, the means of random samples from the population will be normally distributed with the population mean as its mean.
Can the variance of a normally distributed random variable be negative?
No. The variance of any distribution is the sum of the squares of the deviation from the mean. Since the square of the deviation is essentially the square of the absolute value of the deviation, that means the variance is always positive, be the distribution normal, poisson, or other.
