Answer:
b. The values X and Y are independent therefore, the mean is 34 seconds and the standard deviation is 50 seconds
Step-by-step explanation:
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Before the training, the mean running time for the students to run a mile was 402 seconds with standard deviation 40 seconds.
This means that 
After completing the program, the mean running time for the students to run a mile was 368 seconds with standard deviation 30 seconds.
This means that 
Which of the following is true about the distribution of X-Y?
They are independent, so:
This means that the correct answer is given by option b.
Answer:
$45
Step-by-step explanation:
We are given the following information;
- Money invested (Principal) is $300
- Rate of interest is 5% per annum
- Time the money is invested is 3 years
We need to determine the amount of interest the money will earn after three years.
- Simple interest is calculated by the formula;
- Simple interest =(PRT) ÷ 100, Where P is the principal amount, R is the rate of interest and T is the time.
Therefore, in this case;
Simple interest = ($300 × 5 × 3) ÷ 100
= $45
Thus, the money invested earned a simple interest of $45
To simplify the given radical form, we must recall some properties of exponents as shown below.
1. 1/x⁻ⁿ = xⁿ
2. x¹/² = √x
Now, going back to 1/x⁻³/⁶, we have
1/x⁻³/⁶ = x³/⁶
x³/⁶ = x¹/²
x¹/² = √x
Using the properties provided, we have a simplified form of √x.
<span>Answer: √x</span>
