Answer:
s=-2
Step-by-step explanation:
Explanation in picture
X=3
y=6
y=2x
2/3=2x
(2/3)/2=x
(2/3)×(1/2)=x
2/6=x
x=1/3
To solve this, we use the z test.
The formula:
z = (x – u) / s
where x is sample value = 20, u is the mean = 15, and s is
the standard deviation = 2.5
z = (20 – 15) / 2.5
z = 2
Since we are looking for values greater than 20, this is
right tailed test. We use the standard distribution tables to find for P.
P = 0.0228
Therefore:
number of students = 100 * 0.0228 = 2.28
<span>2 to 3 students will get greater than 20 measurement</span>
Answer:
y = 9
Step-by-step explanation:
Collect the like terms:
2y = 18
Divide both sides by 2 to make y on its own
y = 9
Answer:
7 hours
Step-by-step explanation:
Step one:
given data
let the total charges be y and the number of hours be x
Company A charges
$60 reservation fee plus another $15 per hour.
so
y=60+15x----------1
Company B charges
$25 reservation fee plus another $20 per hour
y=25+20x------------2
Step two:
equate the 2 expressions above we have
60+15x=25+20x
collect like terms
60-25=20x-15x
35=5x
divide both sides by 5
x= 35/5
x= 7 hours