Answer: 
Step-by-step explanation:
As per given , we have
n = 11

Since population standard deviation is missing, so we use t-test.
Critical t-value for 99% confidence :
[using two-tailed t-value table]
Confidence interval :

Hence, 99% confidence interval for the mean amount of time that students spend in the shower each day.= 
Answer:
±5sqrt(2) =x
Step-by-step explanation:
65=15+x^2
Subtract 15 from each side
65-15=15-15+x^2
50 = x^2
Take the square root of each side
±sqrt(50) = sqrt(x^2)
±sqrt(25*2) =x
±sqrt(25)sqrt(2) =x
±5sqrt(2) =x
Answer:
$ 3 left ashley money
$ 1 left jacks money
$ 8 left ashley money
$ 4 left jacks money
Step-by-step explanation
3 pencils + 6 rulers = 12 - 9 = 3
5 pencils + 2 rulers = 8 - 7 = 1
12 - 4 = 8
8 - 4 = 4
Answer:
20 hours
Step-by-step explanation: