Answer:

Step-by-step explanation:
We just need to add like terms together



Answer:
27
Step-by-step explanation:
Let's call boys and girls 3x and x respectively. Since 3x + x = 36, x = 9. Boys = 3x = 3 * 9 = 27.
Answer: 
Step-by-step explanation:
Given : sample size : n= 51
sample standard deviation : s= 0.46
Significance level : 
Using chi-square distribution, the critical values will be :


Confidence interval for population standard deviation (
) :

Substitute all the values , we get

Hence, the 95% two-sided confidence interval for σ : 
She would use n-4=7q to find how many quarters in each roll.