For one pack of guitar strings, it cost $14.00
Answer:

The solution of the system can be given as (5,-8).
Step-by-step explanation:
Given system of equations:


To solve the given system of equations:
Solution:
We will use substitution to solve the given system.
We will substitute the
values in terms of
from the equation
into the other equation to solve for 
Substituting
into
.
We have:

<em>Using distribution.</em>

<em>Combining like terms.</em>

Adding 6 both sides.


Dividing both sides by 3.

∴ 
<em>Plugging in
into
.</em>
We have,

∴ 
The solution of the system can be given as (5,-8).
Answer:
A sample size of 79 is needed.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.
In which
z is the zscore that has a pvalue of
.
For this problem, we have that:

The margin of error is:
95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
What sample size is needed if the research firm's goal is to estimate the current proportion of homes with a stay-at-home parent in which the father is the stay-at-home parent with a margin of error of 0.09?
A sample size of n is needed.
n is found when M = 0.09. So






Rounding up to the nearest whole number.
A sample size of 79 is needed.
Answer:
-4 <n <= 5
Step-by-step explanation:
Open at -4 and closed at 5 on number line so the inequality should be
-4 <n <= 5
Isn’t it the example part?