Answer:
option (c) The mean age will stay the same but the variance will decrease
Step-by-step explanation:
Case I: For 3 executives of ages 56, 57 and 58
Number of executives, n = 3
Mean =
or
Mean = 57
Variance =
or
Variance =
or
Variance =
or
Variance = 1
For Case II: For 4 executives of ages 56, 57, 58 and 57
Number of executives, n = 4
Mean =
or
Mean = 57
Variance =
or
Variance =
or
Variance =
or
Variance = 0.67
Hence,
Mean will remain the same and the variance will decrease
Hence,
The correct answer is option (c) The mean age will stay the same but the variance will decrease
The answer you are looking for is A. 7.00. The cost of the item should be $6.00 as the tax should be $0.48. Making the total cost of the item $6.48.
Take the second equation and flip it around so the y on the left ends up on the right and the 4x on the right ends up on the left. This makes all negatives positive and all positives negative. -4x + 12 = y
Then add the first equation to the second equation
4x +12 = -7y
<u>-4x + 12 </u>=<u> y </u> this eliminates the x's
<u>24</u> = -<u> 6y</u> then divide by - 6
- 6 - 6
- 4 = y<u>
</u>So if you know that y = negative 4, you can substitute into either equation. I pick the second one because I am a lazy person.
-y + 12 = 4 x
-(-4) + 12 = 4 x combine your numbers<u>
</u> <u> 16 </u> = <u>4 x </u> then divide by 4<u>
</u> 4 = x
So your solution is: x = 4 and y = -4 or this is also written (4, -4)
Does that work for you?
Divide all the ratios and compare:
8/12 = 0.666
15/10 = 1.5
2/3 = 0.666
6/9 = 0.666
The one that isn't equivalent is 15 over 10