You have the final sales figures for the four quarters in 2010 for Bennets Used Auto Sales, and you are to design a program that asks for the sales figures, computes the total sales for the year, and calculates and displays the average quarterly sales for the year. using pseudocode, develop an algorithm and then convert the pseudocode to JavaScript.

Sure! Here's the pseudocode algorithm to compute the total sales for the year and the average quarterly sales:

Pseudocode:
1. Initialize totalSales and averageSales variables to zero.
2. Create an empty salesArray to hold the sales figures for each quarter.
3. Create a loop that iterates four times, representing the four quarters.
a. Prompt the user to enter the sales figure for each quarter.
b. Read the input and store it in a variable sales.
c. Add the sales figure to the salesArray.
d. Add the sales figure to the totalSales variable.
4. Calculate the average quarterly sales by dividing the totalSales by 4.
5. Display the totalSales and averageSales to the user.

Now, let's convert this pseudocode into JavaScript:

JavaScript:
let totalSales = 0;
let averageSales = 0;
let salesArray = [];

for (let i = 0; i < 4; i++) {
let sales = parseInt(prompt("Enter the sales figure for quarter " + (i + 1) + ":"));
salesArray.push(sales);
totalSales += sales;
}

averageSales = totalSales / 4;

console.log("Total sales for the year: " + totalSales);
console.log("Average quarterly sales: " + averageSales);

In this JavaScript implementation, we use a for loop to iterate four times, prompting the user to enter the sales figure for each quarter. The sales figures are stored in the salesArray, and the totalSales is calculated by adding each sales figure. Finally, the averageSales is calculated by dividing the totalSales by 4. The console.log statements display the total sales and average quarterly sales to the user.