-7d > 21
d < -3
Remember the sign flips when you multiply or divide by a negative number.
Answer:
(4, 1)
Step-by-step explanation:
3x+4y=16 /*4
-4x-3y= - 19 /*3
12x + 16y = 64
<u>- 12x - 9y = - 57 </u>
7y = 7
y = 1
3x+4y=16
3x + 4*1 = 16
3x = 16 - 4
3x = 12
x = 4
Answer:
2 x 6 = 12
5 x 7 = 35
12/35
Step-by-step explanation:
Answer:
B
Step-by-step explanation:
The formula for the volume of a cylinder is
, where r is the radius of the base and h is the height of the cylinder.

Therefore, the correct answer is choice B. Hope this helps!
Answer:
The standard error of the mean is 4.5.
Step-by-step explanation:
As we don't know the standard deviation of the population, we can estimate the standard error of the mean from the standard deviation of the sample as:

The sample is [30mins, 40 mins, 60 mins, 80 mins, 20 mins, 85 mins]. The size of the sample is n=6.
The mean of the sample is:

The standard deviation of the sample is calculated as:

Then, we can calculate the standard error of the mean as:
