Answer:
t=13
Step-by-step explanation:
the ratio of the shorter sides is t/4 and the ratio of the longer sides is 26/8 so t=26×4/8=104/8=13
Answer:
x = 11
Step-by-step explanation:
- Vertically opposite angles are equal
- Angles around a point add up to 360°
Therefore, ![15x + 15x + 15 + 15 = 360](https://tex.z-dn.net/?f=15x%20%2B%2015x%20%2B%2015%20%2B%2015%20%3D%20360)
![\implies 30x+30=360](https://tex.z-dn.net/?f=%5Cimplies%2030x%2B30%3D360)
![\implies 30x=330](https://tex.z-dn.net/?f=%5Cimplies%2030x%3D330)
![\implies x=11](https://tex.z-dn.net/?f=%5Cimplies%20x%3D11)
Answer: x = 28
Step-by-step explanation:
Let's solve your equation step by step!
3/8x + 15/2 = 18
Step 1: Subtract 15/2 from both sides.
3/8x + 15/2 - 15/2 = 18 - 15/2
3/8x = 21/2
Step 2: Multiply both sides by 8/3
(8/3) * (3/8x) = (8/3) * (21/2)
Step 3. Calculate
x = 28
Answer: 10/24
Hope that help :)
Answer:
The 80% confidence interval for the mean number of words a third grader can read per minute is between 40.4 wpm and 40.8 wpm.
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:
![\alpha = \frac{1-0.8}{2} = 0.1](https://tex.z-dn.net/?f=%5Calpha%20%3D%20%5Cfrac%7B1-0.8%7D%7B2%7D%20%3D%200.1)
Now, we have to find z in the Ztable as such z has a pvalue of
.
So it is z with a pvalue of
, so ![z = 1.28](https://tex.z-dn.net/?f=z%20%3D%201.28)
Now, find M as such
![M = z*\frac{\sigma}{\sqrt{n}}](https://tex.z-dn.net/?f=M%20%3D%20z%2A%5Cfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D)
In which
is the standard deviation of the population and n is the size of the sample.
![M = 1.28*\frac{4.1}{\sqrt{840}} = 0.2](https://tex.z-dn.net/?f=M%20%3D%201.28%2A%5Cfrac%7B4.1%7D%7B%5Csqrt%7B840%7D%7D%20%3D%200.2)
The lower end of the interval is the sample mean subtracted by M. So it is 40.6 - 0.2 = 40.4 words per minute.
The upper end of the interval is the sample mean added to M. So it is 40.6 + 0.2 = 40.8 words per minute.
The 80% confidence interval for the mean number of words a third grader can read per minute is between 40.4 wpm and 40.8 wpm.