24 students and teachers rode to the zoo in vans and 385 students and teachers rode to the zoo in buses.
Step-by-step explanation:
Given,
Total number of students and teachers = 409
Students and teachers in each bus = 55
Students and teachers in each van = 12
Let,
x be the number of buses
y be the number of vans
55x+12y=409 Eqn 1
x = y+5 Eqn 2
Putting value of x from Eqn 2 in Eqn 1
Dividing both sides by 67
Putting y=2 in Eqn 2
Number of students and teachers who rode in vans = Number of vans * Teachers and student in each van
Number of students and teachers who rode in vans = 12*2 = 24
Number of students and teachers who rode in buses = 7*55 = 385
24 students and teachers rode to the zoo in vans and 385 students and teachers rode to the zoo in buses.
Keywords: linear equation, substitution method
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Answer:
He used 77 ounces of blue paint
Step-by-step explanation:
In this question, we are to calculate the ounces of blue paint used based on the ratio in the question.
Firstly we add all the ratios together
This gives; 10 + 22 + 4 + 18 = 54
The ratio that represents that of the blue paint is 22;
Thus the number of ounces of blue paints used is; 22/54 * 189 = 77 ounces
Answer:
The 99% confidence interval for the true percentage of all adults in the town that smoke is (0.1159, 0.2841).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of 
, and a confidence interval 
, 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:
Of 150 adults selected randomly from one town, 30 of them smoke. This means that 
99% confidence interval
So 
, z is the value of Z that has a pvalue of 
, so 
.
The lower limit of this interval is:
The upper limit of this interval is:
The 99% confidence interval for the true percentage of all adults in the town that smoke is (0.1159, 0.2841).
x/3 = 5
If you multiply both sides by 3, you get
x = 15
