Answer:
40
Step-by-step explanation:
80/2=40
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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Answer:
278.25 cm2
Step-by-step explanation:
If the width of the rectangle is x (cm), as the length is 8cm longer, so that the length of the rectangle is: x + 8 (cm).
In the attached image, we can see the length of each side. Total length of the sides are 90 cm.
=> (x + x + 8) + x + 8 + (x+8) + (x + x + 8) + x + 8 + (x +8) = 90
=> 8x + 48 = 90
=> 8x = 90 - 48 = 42
=> x =42/8 = 5.25 (cm)
=> The width of the rectangle is 5.25cm
=> The length of the rectangle is: 5.25 + 8 = 13.25 cm
=> The area of one rectangle is: Length x Width = 5.25 x 13.25 = 69.5625 cm2
As the 8-sided shape is made from 4 rectangles, so that:
Area of 8 sided shape = 4 x Area of the rectangle = 4 x 69.5625 = 278.25 cm2