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:1,750,000,000
Step-by-step explanation:first the number ten to the fifth power is 1,000,000 then times five is 5,000,000. Then the number ten to the negative fifth power is 50 times seven is 350. 5,000,000 times 350 is 1,750,000,000
Sorry, my answer was wrong. I can't delete it so as not confuse anybody i changed it to this.
Answer:
140 ways
Step-by-step explanation:
4 x 5 x 7 = 140
Answer:
1,2,3
Step-by-step explanation:
1*8=8+4+12<28
2*8=16+4=20<28
3*8=24+4=28=28