Answer & Step-by-step explanation:
So if 14% are over 65, and 320 residents are over 65, then we can say that 14% of the town is 320. Then, we can divide by 14 to find 1%, which is 22.857142857 Now we can multiply this by 100 to get 2285.7142857, which is the answer. To double check, you'd just find 14% of 2285.7142857 (multiply by 0.14) which is equal to 320. Because you can't have fractions of people, however, you'd have to round the answer up to 2286 people.
If that is too difficult to understand them hope this is easier
14% of the towns population is 320. Let P denote the towns population.
14/100 * P =320
14P/100 = 320
14P = 32000
divide both sides by 14
P = 2285.71
the towns population is 2286
Hope this helps!
Step-by-step explanation:
-x/3 < -4
-x < -12
x > 12
5x +11 ≤ -4
5x ≤ -4-11
5x ≤ -15
x ≤ -3
therefore, the solution is
x ≤ -3 or x > 12
Answer:
0.33333
Step-by-step explanation:
Answer: (110.22, 125.78)
Step-by-step explanation:
The confidence interval for the population mean is given by :-
![\mu\ \pm z_{\alpha/2}\times\dfrac{\sigma}{\sqrt{n}}](https://tex.z-dn.net/?f=%5Cmu%5C%20%5Cpm%20z_%7B%5Calpha%2F2%7D%5Ctimes%5Cdfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D)
Given : Sample size = 463
![\mu=118\text{ minutes}](https://tex.z-dn.net/?f=%5Cmu%3D118%5Ctext%7B%20minutes%7D)
![\sigma=65\text{ minutes}](https://tex.z-dn.net/?f=%5Csigma%3D65%5Ctext%7B%20minutes%7D)
Significance level : ![\alpha=1-0.99=0.01](https://tex.z-dn.net/?f=%5Calpha%3D1-0.99%3D0.01)
Critical value : ![z_{\alpha/2}=z_{0.005}=\pm2.576](https://tex.z-dn.net/?f=z_%7B%5Calpha%2F2%7D%3Dz_%7B0.005%7D%3D%5Cpm2.576)
We assume that the population is normally distributed.
Now, the 90% confidence interval for the population mean will be :-
![118\ \pm\ 2.576\times\dfrac{65}{\sqrt{463}} \\\\\approx118\pm7.78=(118-7.78\ ,\ 118+7.78)=(110.22,\ 125.78)](https://tex.z-dn.net/?f=118%5C%20%5Cpm%5C%202.576%5Ctimes%5Cdfrac%7B65%7D%7B%5Csqrt%7B463%7D%7D%20%5C%5C%5C%5C%5Capprox118%5Cpm7.78%3D%28118-7.78%5C%20%2C%5C%20118%2B7.78%29%3D%28110.22%2C%5C%20125.78%29)
Hence, 99% confidence interval for the mean study time of all first-year students = (110.22, 125.78)
Answer:
Step-by-step explanation:
Let the age be xy or 10x + y.
Reverse the two digits of my age, divide by three, add 20, and the result is my age, convert this to equation:
- (10y + x)/3 + 20 = 10x + y
- (10y + x)/3 = 10x + y - 20
- 10y + x = 3(10x + y - 20)
- 10y + x = 30x + 3y - 60
- 30x - x + 3y - 10y = 60
- 29x - 7y = 60
We should consider both x and y are between 1 and 9 since both the age and its reverse are 2-digit numbers.
Possible options for x are:
- 29x ≥ 7*1 + 60 = 67 ⇒ x > 2, at minimum value of y,
and
- 29x ≤ 7*9 + 60 = 123 ⇒ x < 5, at maximum value of y.
So x can be 3 or 4.
<h3>If x = 3</h3>
- 29*3 - 7y = 60
- 87 - 7y = 60
- 7y = 27
- y = 27/7, discarded as fraction.
<h3>If x = 4</h3>
- 29*4 - 7y = 60
- 116 - 7y = 60
- 7y = 56
- y = 8
So the age is 48.