Good job, you got the equations! XD
I'll just help you solve
Multiply the 2nd row by 9
<span>9x+9y=117</span>
<span><span><span>9x+27y=207
</span></span></span>Subtract the 2nd row from the 1st row
<span><span><span>−18y=−90
</span></span></span>Divide both sides by <span>−18</span>
<span><span><span>y=<span><span>−90/</span><span>−18
</span></span></span></span>Two negatives make a positive
<span><span>y=<span><span>90/</span><span>18</span></span></span><span></span></span><span>
y = 5
Substitute 5 into an equation
9x+9(5)=11<span>7
</span>9x+45=11<span>7
</span>Subtract <span>45</span> from both sides
<span><span><span>9x=117−45
</span></span></span>9x=7<span>2
</span>Divide both sides by <span><span>9</span></span>
x = ___
Hope this will help</span></span>
.5 because first you add 1 on each side, that gets rid of the 1 on the left. then divide by 4
Answer:
C. x > 3
Step-by-step explanation:
As long as you don't multiply or divide by any negative numbers*, <em>you can solve this the same way you would an equation</em>.
3x +2 > x +8
3x > x +6 . . . . . . subtract 2
2x > 6 . . . . . . . . subtract x
x > 3 . . . . . . . . . .divide by 2; matches choice C
_____
* The complete rule is "as long as you don't use any order-changing operations, ...". There are some functions you can apply to both sides of the inequality that will change the ordering. Multiplication or division by a negative number is only one of many.
1 < 2
-1 > -2 . . . . . multiplication by -1 reverses the order
Answer:
a) 17.09 hours
b) The 95% confidence interval estimate of the population mean flying time for the Pilots is between 31.91 hours and 66.09 hours
Step-by-step explanation:
We have the standard deviation of the sample, so we use the t distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 49 - 1 = 48
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 48 degrees of freedom(y-axis) and a confidence level of 
. So we have T = 2.0106
The margin of error is:
M = T*s = 2.0106*8.5 = 17.09
s is the standard deviation of the sample. 17.09 hours is the answer for a.
The lower end of the interval is the sample mean subtracted by M. So it is 49 - 17.09 = 31.91 hours
The upper end of the interval is the sample mean added to M. So it is 49 + 17.09 = 66.09 hours
The 95% confidence interval estimate of the population mean flying time for the Pilots is between 31.91 hours and 66.09 hours
