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: the player answered 30 questions correctly.
Step-by-step explanation:
Let x represent the number of questions that the player answered correctly.
Let y represent the number of questions that the player answered incorrectly.
The number of questions that the player answered is 40. It means that
x + y = 40- - - - - - - - - - -1
The score on the trivia game is obtained by subtracting the number of incorrect answers from twice the number of correct answers. If the player obtained a score of 50, It means that
2x - y = 50
y = 2x - 50
Substituting y = 2x - 50 into equation 1, it becomes
x + 2x - 50 = 40
3x - 50 = 40
3x = 40 + 50 = 90
x = 90/3
x = 30
It will take her around 126 minutes
Try to list the questions out. That will help good luck!
