The answer is 21x-25 because all you have to do is multiply the 1/4 by the 84x and then multiply 1//4 by negative 100. A simpler way of explaining this is just that you need to distribute
The probability the sample mean is more than 10 words for a random sample of 39 messages is 2.12%
<h3>What is an
equation?</h3>
An equation is an expression that shows the relationship between two or more numbers and variables.
The z score is given by:
z = (raw score - mean) / (standard deviation / √sample size)
Given mean of 8.6 words and a standard deviation of 4.3 words. If a random sample of 39 messages, hence, for x > 10:
z = (10 - 8.6) / (4.3 / √39) = 2.03
P(x > 10) = P(z > 2.03) = 1 - P(z < 2.03) = 1 - 0.9788 = 0.0212
The probability the sample mean is more than 10 words for a random sample of 39 messages is 2.12%
Find out more on equation at: brainly.com/question/2972832
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