Answer:
Step-by-step explanation
- Let x be the number of adults and y the number of kids
We can then write this two equations :
x+y= 33
15x+7y= 311
- let's solve the two eaquations
to do that we should combine them both in a way that help us get rid of one of the variables.
Let's multiply the first equation by -7 to get rid of y by adding it to thr second equation
-7x-7y= -231
now add both equations .
15x+7y-7x-7y=311-231
we get : 8x = 80
as you notice y is gone and we get a classic easy equation to solve
x= 80/8
= 10
so the number of adults is 10
let's go back to the first equation ( x+y= 33) and replace x with 10
10+y= 33
y= 33-10
=23
let's check using the second equation :
(10*15)+(23*7) = 311
that is true
so :
- the number of adults is 10
- the number of kids is 23
Answer:
95% confidence interval for the mean number of months is between a lower limit of 6.67 months and an upper limit of 25.73 months.
Step-by-step explanation:
Confidence interval is given as mean +/- margin of error (E)
Data: 5, 15, 12, 22, 27
mean = (5+15+12+22+27)/5 = 81/5 = 16.2 months
sd = sqrt[((5-16.2)^2 + (15-16.2)^2 + (12-16.2)^2 + (22-16.2)^2 + (27-16.2)^2) ÷ 5] = sqrt(58.96) = 7.68 months
n = 5
degree of freedom = n-1 = 5-1 = 4
confidence level (C) = 95% = 0.95
significance level = 1 - C = 1 - 0.95 = 0.05 = 5%
critical value (t) corresponding to 4 degrees of freedom and 5% significance level is 2.776
E = t×sd/√n = 2.776×7.68/√5 = 9.53 months
Lower limit of mean = mean - E = 16.2 - 9.53 = 6.67 months
Upper limit of mean = mean + E = 16.2 + 9.53 = 25.73 months
95% confidence interval is (6.67, 25.73)
Answer:
Height = 3.82
Step-by-step explanation:
(3.14)(5)²
(3.14)(25)
= 78.5
300 = 78.5h
300/78.5 = 78.5h/78.5
h = 3.821656051 or approximately 3.82
If your asking for what that would be called cause I don't understand what your asking but it would be called the midpoint
