IN JAVA: Build a class called ExamPractice from scratch. This class should include a main method that does the following:

1. Prompt the user to enter a number of inches
2. Read the number of inches entered from the console
3. Convert the inches into an equivalent number of miles, yards, feet, and inches.
4. Output the results to the console.

For example, if a user entered 100000 inches, the program would output:

100000 inches is equivalent to:

Miles: 1

Yards: 1017

Feet: 2

Inches: 4

1.

1). Three point charges are located along the x-axis; -2.0 nC at x = -2.0 m, +5.0 nC at x = +3.0 m, and 1.0 nC at x = 1.0 m. Calculate the net electric field for both magnitude AND direction at the origin due to these three source charges. NOTE: (+) means pointing to the right and (-) means pointing to the left in terms of the field

Calculation of pH after Titration of Weak Acid: Calculation of pH after Titration of Weak Acid: A compound has a p K a of 7.4. To 100 mL of a 1.0 M solution of this compound at pH 8.0 is added 30 mL of 1.0 M hydrochloric acid. What is the pH of the resulting solution?

Can you explain what to do after 3.98 = A/HA

Calculate the mass of solid sodium acetate and how much of 1.0 M of acetic acid required to mix with 100.0 mL to prepare a pH 4 buffer and total common ion concentration= 0.200 M (Show all work). 1. How many grams of solid sodium acetate is needed? 2. How much mL of 1.0 M acetic acid is needed?

For each pair of substances determine which has the higher entropy per mole of substance.

a. H2O (s) at 200 K or H2O(s) at 298 K.

b. H2(g) at 298 K, 2.0 atm or H2(g) at 298 K, 1.0 atm.

c. H2(g) at 298 K, 5.0 L or H2(g) at 298 K, 1.0 L

The following charges exist (given coordinates are (x, y) coordinates in the plane of the page):

• a −3.0 µC point charge located at (0, 0)

• a −2.0 µC uniform spherical shell of charge of radius 3.0 cm centered at (+4.0 cm, 0)

• a +2.0 µC uniform spherical shell of charge of radius 2.0 cm centered at (0, −4.0 cm)

• a +4.0 µC uniform spherical shell of charge of radius 4.0 cm centered at (−1.0 cm, +1.0 cm)

(a). Calculate the net electric force (magnitude and direction) acting on the −3.0 µC point charge.

(b). Suppose you were given a +1.0 µC charge to add to the arrangement of charges above. Your goal is to place the charge so that the net force on the −3.0 µC charge is zero. Where would you put the +1.0 µC charge? Be specific.

(c). The −3.0 µC point charge was created by either adding or removing electrons from a neutral object. Were electrons added or removed? How many electrons were added or removed?

The accompanying data shows the weekly purchases of printers at a particular electronic store. Using α = ​0.05, perform a​ chi-square test to determine if the number of printers sold per week follows a normal probability distribution. Note that x = 11.3 and s = 4.6.

Use the intervals below to calculate the​ chi-square test​ statistic, χ2

Calculate the test statistic

χ2 =

​(Round to two decimal places as​ needed.)

Determine the​ p-value.

​p-value =

​(Round to three decimal places as​ needed.)

Run the following code and explain the results (expectation of the array). Test it on the following arrays: [1.0, 2.0, 3.0, 4.0, 5.0, 6.0] [1.0, 4.0, 6.0,2.0 , 3.0, 5.0] [5.0, 3.0, 2.0, 6.0, 4.0, 1.0] [6.0, 5.0, 4.0, 3.0, 2.0, 1.0] // Java code to calculate expected // value of an array import java.io.*; class GFG { // Function to calculate expectation static float calc_Expectation(float a[], float n) { // Variable prb is for probability of each // element which is same for each element float prb = (1 / n); // calculating expectation overall float sum = 0; for (int i = 0; i < n; i++) sum += a[i] * prb; // returning expectation as sum return sum; } // Driver program public static void main(String args[]) { float expect, n = 6f; float a[] = { 1f, 2f, 3f, 4f, 5f, 6f }; // Function for calculating expectation expect = calc_Expectation(a, n); // Display expectation of given array System.out.println("Expectation of array E(X) is : " + expect); } }

4. Derek is the owner of the only movie theater in town. By hiring several well-trained economists, Derek learns that the people watching movies after 8 P.M. have a much higher average willingness to pay than people watching at 5 P.M. The costs of showing a movie are identical at 5 P.M. and 8 P.M. To maximize his profit, what should Derek do? Give him some specific advice, including drawing him a diagram or two. (Derek can get his economists to interpret your diagrams as long as you label all the axes and all the curves.)