Answer:
Mary = 24
Chau = 15
David = 48
Step-by-step explanation:
The formula is
Mary + Chau + David = 87
And we know that
Chau = Mary - 9
David = Mary * 2
So when we fill this in
Mary + Mary - 9 + Mary * 2 = 87
4Mary - 9 = 87
4Mary = 96
Mary = 24
Chau = Mary - 9 = 15
David = Mary * 2 = 48
Answer:
They bike 18 kilometers
Step-by-step explanation:
25-2+5=18
Answer:
118.6
Step-by-step explanation:
Total calories to burn = 700
Total calories burnt = 581.4
Remaining Calories = 700 - 581.4 = 118.6
Answer:
The 95% confidence interval for the mean score, , of all students taking the test is

Step-by-step explanation:
From the question we are told that
The sample size is 
The mean score is 
The standard deviation 
Generally the standard deviation of mean is mathematically represented as

substituting values


The degree of freedom is mathematically represented as

substituting values


Given that the confidence interval is 95% then the level of significance is mathematically represented as

5%

Now the critical value at this significance level and degree of freedom is

Obtained from the critical value table
So the the 95% confidence interval for the mean score, , of all students taking the test is mathematically represented as

substituting value

