Daily Life Magazine wants an analysis of the demographic characteristics of its readers. The Marketing Department has collected reader survey records containing the age, gender, marital status, and annual income of readers. Design an application that accepts reader data and produces a count of readers by age groups as follows: under 20, 20-29, 30-39, 40-49, and 50+

Here's a little perl program which does the job. You can format and sort the output as needed.

my $agegroup;
while ($_ = <DATA>) {
print "Enter age, sex, status, income: $_";
my $age = (split)[0];
my $ag = int($age/10);
$ag = 1 if $ag < 2; # count 0-10 as teens (under 20)
push @{$agegroup->{$ag}}, $_;
}
close DATA;
foreach my $ag (sort keys %$agegroup) {
my $agk = ($ag<2) ? "Under 20" : sprintf("%d-%d",10*$ag,10*$ag+9);
my $cnt = @{$agegroup->{$ag}};
print "$agk: $cnt\n";
foreach my $rec (@{$agegroup->{$ag}}) {
print " $rec";
}
}

Here is the output from a sample run:

Enter age, sex, status, income: 46 M M 37000
Enter age, sex, status, income: 17 M D 36000
Enter age, sex, status, income: 31 M S 164000
Enter age, sex, status, income: 41 F D 295000
Enter age, sex, status, income: 51 M M 198000
Enter age, sex, status, income: 15 M M 55000
Enter age, sex, status, income: 66 M S 73000
Enter age, sex, status, income: 50 M D 161000
Enter age, sex, status, income: 62 M S 96000
Enter age, sex, status, income: 28 M D 232000
Enter age, sex, status, income: 46 M D 92000
Enter age, sex, status, income: 48 M S 186000
Enter age, sex, status, income: 37 M D 100000
Enter age, sex, status, income: 51 F D 193000
Enter age, sex, status, income: 20 F D 202000
Enter age, sex, status, income: 66 F M 264000
Enter age, sex, status, income: 28 F S 280000
Enter age, sex, status, income: 20 M M 33000
Enter age, sex, status, income: 39 F S 280000
Enter age, sex, status, income: 27 F S 187000
Enter age, sex, status, income: 61 F M 272000
Enter age, sex, status, income: 46 F M 41000
Enter age, sex, status, income: 31 M S 305000
Enter age, sex, status, income: 31 M M 145000
Enter age, sex, status, income: 67 M M 313000
Enter age, sex, status, income: 35 F M 235000
Enter age, sex, status, income: 34 M S 106000
Enter age, sex, status, income: 47 M D 182000
Enter age, sex, status, income: 65 M S 90000
Enter age, sex, status, income: 48 M S 273000
Under 20: 2
17 M D 36000
15 M M 55000
20-29: 5
28 M D 232000
20 F D 202000
28 F S 280000
20 M M 33000
27 F S 187000
30-39: 7
31 M S 164000
37 M D 100000
39 F S 280000
31 M S 305000
31 M M 145000
35 F M 235000
34 M S 106000
40-49: 7
46 M M 37000
41 F D 295000
46 M D 92000
48 M S 186000
46 F M 41000
47 M D 182000
48 M S 273000
50-59: 3
51 M M 198000
50 M D 161000
51 F D 193000
60-69: 6
66 M S 73000
62 M S 96000
66 F M 264000
61 F M 272000
67 M M 313000
65 M S 90000

To design an application that accepts reader data and produces a count of readers by age groups, you can follow these steps:

Step 1: User Interface
Create a user interface where the Marketing Department can input reader data. This can be a simple form with fields to enter age, gender, marital status, and annual income. Additionally, you can include a button to submit the data.

Step 2: Data Storage
Set up a data storage system, such as a database, to store the reader data. Each record should include the age, gender, marital status, and annual income.

Step 3: Data Processing
When the user submits the reader data, your application should process it to generate the count of readers by age groups.

First, retrieve the reader records from the data storage system.

Next, iterate through each record and categorize the readers into age groups. Depending on the programming language you're using, you can use conditional statements or mathematical comparisons to determine the age group for each reader.

For example:
- If the reader's age is under 20, increment the count for the "under 20" age group.
- If the reader's age is between 20 and 29, increment the count for the "20-29" age group.
- And so on...

Step 4: Displaying the Results
Once the data processing is complete, display the count of readers by age groups to the user. This can be in the form of a table or a chart that shows each age group along with its corresponding count.

For example:

Age Group | Count
--------------------
Under 20 | 50
20-29 | 100
30-39 | 75
40-49 | 60
50+ | 80

You can update this display whenever new reader data is submitted to keep an up-to-date analysis of the demographic characteristics of readers.

Remember to add error handling and data validation to your application to ensure the input data is correct and complete.