Answer:
Critical value t-score=2.701.
Step-by-step explanation:
When we calculate a confidence interval with an unknown population standard deviation, we estimate it from the sample standard deviation and use the t-score instead of the z-score.
The critical value for t depends on the level of confidence and the degrees of freedom.
If the sample size is 42, the degrees of freedom are:

For a confidence level of 99% and 41 degrees of freedom, the critical value of t is t=2.701.
For this case, the first thing we must do is define variables.
x: amount of time Miguel uses to complete the task.
y: amount of time Maria uses to complete the task.
We write the system of equations:
x + y = 60
y = (1/2) x
Solving the system we have:
x = 40 minutes
y = 20 minutes
Answer:
it take her to wash them by herself about:
y = 20 minutes
Since the rectangles are colored in, we can take the area of each color, then add them together. To find all the lengths and widths, subtract as needed: Since the center rectangle's length is 10 feet, subtract 10 from the length of the room which is 16 feet. Those 6 units must be divided in half to give 3 feet for the width of the blue rectangle. Similarly, subtract 8 from 12 and divide the 4 in half to give 2 feet for the width of the yellow rectangle. This also reveals the length and width of the green rectangle. The length is 3 and the width 2, so the area is found 3x2=6. The area of the blue rectangle is found 3x10=30. The area of the yellow rectangle is found 13x2=26. Add these areas up: 6+30+26 = 62 square feet.
Answer:
OPtion I is right
Step-by-step explanation:
Once we know sin of an angle, and it lies in II quadrant, we know that
cos, sec, tan and cot would be negative but csc will be positive.
So use the fact that

Thus cos is obtained using negative square root.
Now tan = sin/cos, and sec = 1/cos:
cot =1/tan and csc =1/sin
Thus all value can be obtained easily
So option I
Answer:
chances chances of happening = 0.0119
Step-by-step explanation:
given data
bet = $5
independent fair games = 50
solution
we will think game as the normal distribution
so here mean is will be
mean = 
mean = 25
and standard deviation will be
standard deviation = 
standard deviation = 3.536
so
we have to lose 33 out of 50 time for lose more than $75
so as chance of doing things z score is
z score =
z score = 2.26
so from z table
chances chances of this happening = 0.0119