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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A graph shows the first comparison is true, and the C temperature is cooler than the F temperature for the remaining comparisons.
The comparison that is FALSE is ...
C.....30 °C is warmer than 90 °F
_____
30 °C = 86 °F
32.2 °C ≈ 90 °F
It's 6.9. Just do the circumference divided by pi
Answer:
7
Step-by-step explanation:
This is a Poisson distribution problem with the formula;
P(x;μ) = (e^(-μ)) × (μ^(x))/x!
We are told that the grocer sells three of a certain article per week. Thus;
μ = 3
Now, we want to find out How many of these should he have in stock so that the chance of his running out within a week is less than 0.01.
This means;
P(X > k) < 0.01
This can be rewritten as;
P(X ≤ k) < 0.99
Let's try x = 8
P(8;3) = (e^(-3)) × (3^(8))/8!
P(8;3) = 0.008
But; P(X ≤ 8) = 1 - 0.008 = 0.992
This is more than 0.99 and thus is not the answer
Let's try x = 7
P(7;3) = (e^(-3)) × (3^(7))/7!
P(7;3) = 0.022
But; P(X ≤ 7) = 1 - 0.022 = 0.978
Thus is less than 0.99.
Thus, stock should be 7
