Answer:
Mean: 40.17 years.
Standard deviation: 10.97 years.
Step-by-step explanation:
The frequency distribution is in the attached image.
We can calculate the mean adding the multiplication of midpoints of each class and frequency, and dividing by the sample size.
The midpoints of a class is calculated as the average of the bounds of the class.
Then, the mean can be written as:
The standard deviation can be calculated as:
![s=\sqrt{\dfrac{1}{N-1}\sum f_i(X_i-E(X))^2}\\\\\\s=\sqrt{\dfrac{1}{59}[3(15-40.17)^2+7(25-40.17)^2+18(35-40.17)^2+20(45-40.17)^2+12(55-40.17)^2]}](https://tex.z-dn.net/?f=s%3D%5Csqrt%7B%5Cdfrac%7B1%7D%7BN-1%7D%5Csum%20f_i%28X_i-E%28X%29%29%5E2%7D%5C%5C%5C%5C%5C%5Cs%3D%5Csqrt%7B%5Cdfrac%7B1%7D%7B59%7D%5B3%2815-40.17%29%5E2%2B7%2825-40.17%29%5E2%2B18%2835-40.17%29%5E2%2B20%2845-40.17%29%5E2%2B12%2855-40.17%29%5E2%5D%7D)
Answer:
Option B is correct.
Step-by-step explanation:
Answer:
4,5 miles
Step-by-step explanation:
In 1 hour: 18/3 = 6 miles
6 . 3/4 = 18/4 = 4,5 miles
Answer:
A=670
B=301,600
C=560
Step-by-step explanation:
A is K divided by the wavelength (m) 301,500 / 450
B is wavelength(m) multiplied by the Frequency (Thz) 520x580
C is K divided by the Frenquency (Thz) 302400 / 540
Square root of 88 is 9.38083152
Square root of 95 is 9.746794345
9.38083152 + 9.746794345 = 19.12762586
