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:
t=2x+ 2
Step-by-step explanation:
x is every phone call 2 is how many minutes she spends on each call The other 2 is the 2 minutes she already spended
Answer:
Solutions are 2, -1 + 0.5 sqrt10 i and -1 - 0.5 sqrt10 i
or 2, -1 + 1.58 i and -1 - 1.58i
(where the last 2 are equal to nearest hundredth).
Step-by-step explanation:
The real solution is x = 2:-
x^3 - 8 = 0
x^3 = 8
x = cube root of 8 = 2
Note that a cubic equation must have a total of 3 roots ( real and complex in this case). We can find the 2 complex roots by using the following identity:-
a^3 - b^3 = (a - b)(a^2 + ab + b^2).
Here a = x and b = 2 so we have
(x - 2)(x^2 + 2x + 4) = 0
To find the complex roots we solve x^2 + 2x + 4 = 0:-
Using the quadratic formula x = [-2 +/- sqrt(2^2 - 4*1*4)] / 2
= -1 +/- (sqrt( -10)) / 2
= -1 + 0.5 sqrt10 i and -1 - 0.5 sqrt10 i
Answer:
0, -2 i think :p
Step-by-step explanation:
Because i say so
A = 15000(1.04)6 .........You can put this into your calculator such that it becomes
A = $18,979.79