Using z-scores, it is found that the value of z is z = 1.96.
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Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula, which for a measure X, in a distribution with mean 
and standard deviation 
, is given by:
- It measures how many standard deviations the measure is from the mean.
- Each z-score has an associated p-value, which is the percentile.
- The normal distribution is symmetric, which means that the middle 95% is between the <u>2.5th percentile and the 97.5th percentile</u>.
- The 2.5th percentile is Z with a p-value of 0.025, thus Z = -1.96.
- The 97.5th percentile is Z with a p-value of 0.975, thus Z = 1.96.
- Thus, the value of Z is 1.96.
A similar problem is given at brainly.com/question/16965597
3x - x + 8 + 5x - 2 = 10
combine like terms on the left, then add or subtract as asked
(3x - x + 5x) + (8 - 2) = 10
7x + 6 = 10
subtract 6 from both sides
7x = 4
divide both sides by 7
x = 4/7
Hope this helps! :)
Answer:
5 more people studied more in 0-30 minutes than people who studied 121-120 minutes.
Step-by-step explanation:
Answer:
Right angle
Step-by-step explanation: you take the 57% angle and ad that with
the 33% angle and you got a prefect 90% also known as a "Right angle"
Answer:
2.5% probability that a randomly selected book has fewer than 133 pages.
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 189 pages
Standard deviation = 28 pages
What is the probability that a randomly selected book has fewer than 133 pages?
133 = 189 - 2*28
So 133 is two standard deviations below the mean.
The Empirical Rule states that 95% of the measures are within 2 standard deviations of the mean. The other 5% is more than two standard deviations distant from the mean. The normal distribution is symmetric, which means that of those 5%, 2.5% are more than 2 standard deviations below the mean and 2.5% are more than 2 standard deviations above the mean.
This means that there is a 2.5% probability that a randomly selected book has fewer than 133 pages.
