Answer:
(a) The standard deviation of your waiting time is 4.33 minutes.
(b) The probability that you will have to wait more than 2 standard deviations is 0.4227.
Step-by-step explanation:
Let <em>X</em> = the waiting time for the bus at the parking lot.
The random variable <em>X</em> is uniformly distributed with parameters <em>a</em> = 0 to <em>b</em> = 15.
The probability density function of <em>X</em> is given as follows:

(a)
The standard deviation of a Uniformly distributed random variable is given by:

Compute the standard deviation of the random variable <em>X</em> as follows:




Thus, the standard deviation of your waiting time is 4.33 minutes.
(b)
The value representing 2 standard deviations is:

Compute the value of P (X > 8.66) as follows:





Thus, the probability that you will have to wait more than 2 standard deviations is 0.4227.
Answer:
The 95 percent confidence interval for the mean of the population from which the study subjects may be presumed to have been drawn is (19.1269, 32.6730).
Step-by-step explanation:
Intern No. of Breast
Number Exams Performed X²
1 30 900
2 40 1600
3 8 64
4 20 400
5 26 676
6 35 1225
7 35 1225
8 20 400
9 25 625
<u>10 20 400 </u>
<u> </u><u> ∑ 259 ∑ 7515</u>
Mean= X`= ∑x/n= 259/10= 25.9
Variance = s²= 1/n-1[∑X²- (∑x)²/n]
= 1/0[7515- (259)²/10]= 1/9[7515- 6708.1]
= 806.9/9=89.655= 89.66
Standard Deviation= √89.655= 9.4687
Hence
The value of t with significance level alpha= 0.05 and 9 degrees of freedom is t(0.025,9)= 2.262
The 95 % Confidence interval is given by
x`±t(∝,n-1) s/√n
So Putting the values
25.9± 2.262( 9.4687/√10)
= 25.9 ±2.262 (2.9943)
= 25.9 ± 6.7730
= 25.9 +6.7730=32.6730
25.9 -6.7730= 19.1269
= 19.1269, 32.6730
The 95 percent confidence interval for the mean of the population from which the study subjects may be presumed to have been drawn is (19.1269, 32.6730).
NB- Solution is emboldened
import java.util.Scanner;
import java.util.Random;
public class RandomGenerateNumbers {
public static void main (String [] args) {
Random randGen = new Random();
int seedVal = 0;
seedVal = 4;
randGen.setSeed(seedVal);
System.out.println(randGen.nextInt(50) + 100);
System.out.println(randGen.nextInt(50) + 100);
return;
}
}