7.43: Let 
denote the random variable for height and 
for the sample mean. Then if 
is the mean of
So the probability that the difference between the sample and population means does not exceed 0.5 inch is
per the empirical or 68/95/99.7 rule.
7.44: For a sample of size <em>n</em>, the sample standard deviation would be 
. We want to find <em>n</em> such that
Comparing to the equation from the previous part, this means we would need
so a sample of at least 157 men would be sufficient.
Answer:
Assuming you want to simplify the expression, it can be shortened to:
-k² - 2k
Step-by-step explanation:
What you need to do here is called grouping like terms. Like terms can be described as terms that have the same factors. In this case, the factors we're looking at are k and k²:
Given:
k - 3k² -3k + 2k²
We'll rearrange to group like expressions:
= -3k² + 2k² + k -3k
Pull out common factors:
= (-3 + 2)k² + (1 - 3)k
And simplify:
= -k² - 2k
Answer:
90
Step-by-step explanation:
3/1=3
30x3=90
Answer:
True
Step-by-step explanation:
No need for explanation
Answer:
cos Θ = 
Step-by-step explanation:
Given the angle passes through (4, 5 ) then the right triangle with sides 4 and 5 has hypotenuse h given by
h² = 4² + 5² = 16 + 25 = 41 ( take the square root of both sides )
h = 
In relation to Θ, 4 is adjacent and 5 is opposite, thus
cos Θ = 
=
