12. Khi xác định số đơn vị mẫu cần điều tra để ước lượng số trung bình, nếu không biết phương sai của tổng thể chung thì có thể lấy:

Program description: a c# app is to be created to produce morse code. the morse code assigns a series of dots and dashes to each letter of the alphabet, each digit, and a few special characters (such as period, comma, colon, and semicolon). in sound-oriented systems, the dot represents a short sound and the dash represents a long sound. separation between words is indicated by a space, or, quite simply, the absence of a dot or dash. in a sound-oriented system, a space is indicated by a short period of time during which no sound is transmitted. the international version of the morse code is stored in the data file morse.txt.

What key should you press and hold to select and open multiple files at one time? enter alt control esc

7.23 main lab 7 - online shopping cart background this main lab extends the earlier prep lab "online shopping cart part 1". (you should save this as a separate project from the earlier prep lab). you will create an on-line shopping cart like you might use for your on-line purchases. the goal is to become comfortable with setting up classes and using objects. requirements this lab can be done individually or as pair programming. expanded itemtopurchase class (15 points) extend the itemtopurchase class as follows. we will not do unit testing in this lab so we will not be giving you the names of the member functions. create good ones on your own. create a parameterized constructor to assign item name, item description, item price, and item quantity (default values of "none" for name and description, and 0 for price and quantity). additional public member functions set an item description get an item description print the cost of an item - outputs the item name followed by the quantity, price, and subtotal (see example) print the description of an item - outputs the item name and description (see example) additional private data members a string for the description of the item. example output of the function which prints the cost of an item: bottled water 10 @ $1.50 = $15.00 example output of the function which prints the item description: