Answer:
95% two-sided confidence interval on the true mean breaking strength is (94.8cm, 99.2cm)
Step-by-step explanation:
Our sample size is 11.
The first step to solve this problem is finding our degrees of freedom, that is, the sample size subtracted by 1. So
.
Then, we need to subtract one by the confidence level
and divide by 2. So:

Now, we need our answers from both steps above to find a value T in the t-distribution table. So, with 10 and 0.025 in the two-sided t-distribution table, we have 
Now, we find the standard deviation of the sample. This is the division of the standard deviation by the square root of the sample size. So

Now, we multiply T and s
cm
For the upper end of the interval, we add the sample mean and M. So the upper end of the interval here is
cm
So
95% two-sided confidence interval on the true mean breaking strength is (94.8cm, 99.2cm).
Answer:
Equations:
--- Cindy
--- Ruben
Solution to equation:
Time they have the same amount: 14 minutes
Number of cards they have at that time: 140 flashcards
Step-by-step explanation:
Solving (a): Variables and what they represent
The variables to use are x and y
Where x represent the minutes and y represents the number of flashcards in x minutes
Solving (b): System of linear equation
Cindy:

per minute
Total number of flashcards (y) in x minutes is:



Ruben:
per minute
Total number of flashcards (y) in x minutes is:



Solution to Equations:
Time they have the same amount.
To do this, we
expressions
i.e.

Collect Like Terms


Number of cards they have at that time.
Here, we simply substitute 14 for x in any of the equations.



or




Answer:
1. 125
2. 25
3. 40
4. 39
First question:
(15-10)^2 + (15-5)^2
parentheses first to get 5^2 + (15-5)^2
exponents next to get 25 + (15-5)^2
parentheses again 25 + 10^2
exponents again 25 + 100 = 125
Second question:
simplify the exponents (3 *3) + (4 * 4) + (2 * 2) to get 9 + 16 + 4 = 29
Third question:
simplify in the parentheses 6 1/7 - 1/7 = 6
divide 60 by 6 to get 10
multiply 10 by 4 to get 40!
Fourth question:
simplify the fractions to get 1/3 + 8/3 = 3
multiply the 3 by 13 to get 39