Step-by-step explanation:
65 - 2 × 7 + 9 ÷ 3
65 - 14 + 3
51 + 3 = 54
Option A is the correct answer
Answer:
2. x = 47
3. x = 2
Step-by-step explanation:
These problems involve proportions, or equivalent ratios. You can solve for 'x' in each by using cross-multiplication and division.
2. 28(7) = 4(x + 2)
Distribute = 196 = 4x + 8
Subtract 8 from both sides: 196 - 8 = 4x + 8 - 8 or 188 = 4x
Solve for x: x = 47
3. 2(2x + 7) = 11(3x - 4)
Distribute: 4x + 14 = 33x - 44
Add 44 to both sides: 4x + 14 + 44 = 33x - 44 + 44 or 4x + 58 = 33x
Subtract 4x from both sides: 4x + 58 - 4x = 33x - 4x or 58 = 29x
Solve for x: x = 2
Answer:
A sample of 18 is required.
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Z-table as such z has a p-value of 
.
That is z with a pvalue of 
, so Z = 1.88.
Now, find the margin of error M as such
In which 
is the standard deviation of the population and n is the size of the sample.
A previous study indicated that the standard deviation was 2.2 days.
This means that 
How large a sample must be selected if the company wants to be 92% confident that the true mean differs from the sample mean by no more than 1 day?
This is n for which M = 1. So
Rounding up:
A sample of 18 is required.
Did you learn about cards? I think it is 5 I’m not sure
D. Neither A nor B. There you go.
