There are 7 lengths of at least 20 centimeters
X² - 7x +12 = 0
(x-3)(x-4)=0
x= 3 or 4
since the leading coefficient is positive the parabola opens up and the vertex is a minimum
Answer:
74.30
Step-by-step explanation:
Let s = entry price for a student
Let t = entry price for a teacher
4s +5t = 95
6s+10t = 173
I will use elimination to solve this problem.
Multiply the first equation by -2
-2(4s +5t) = -2*95
Distribute
-8s - 10t = -190
Add this equation to the second equation to eliminate t
-8s - 10t = -190
6s+10t = 173
----------------------
-2s = -17
Divide by -2
-2s/-2 = -17/-2
s = 8.50
Now we need to find t
4s +5t = 95
Substitute s=8.50
4(8.50) +5(t) = 95
34 +5t = 95
Subtract 34 from each side
34-34 +5t = 95-34
5t = 61
Divide by 5
5t/5 = 61/5
t = 12.20
We want to find the cost for 3 students and 4 teachers
3s+4t
3(8.50) + 4(12.20)
25.50 + 48.80
74.30
According to the described situation, it is found that:
1.
,
.
2. Since the interval does not include 32, hence you can reject the null hypothesis and there is enough evidence to conclude that the actual mean flight time of all balloons differ from the advertised 32 hours.
<h3>What are the hypothesis tested?</h3>
At the null hypothesis, it is tested if the mean flight time is of 32 minutes, that is:

At the alternative hypothesis, it is tested if it differs of 32 minutes, hence:

<h3>What is the decision?</h3>
The confidence interval is of (28.5, 31.4), that is, is does not include 32, hence you can reject the null hypothesis and there is enough evidence to conclude that the actual mean flight time of all balloons differ from the advertised 32 hours.
More can be learned about an hypothesis test at brainly.com/question/26454209