Trident Help

Statistics

Find the mean, median and mode

Work out the average (mean), the middle value (median) and the most common value (mode) of a list.

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The mean adds the values and divides by how many there are. The median is the middle value once the list is in order. The mode is the value that appears most often.

The example list is 3, 5, 5, 7, 10. The mean is 6, the median is 5 and the mode is 5.

No calculator here has a one-key mode. To find it, sort the list and look for the value that repeats most.

Classic Graphing 84

Start on the main screen: Press 2nd then mode (QUIT) to get back to the home screen. Pressing clear on a menu also backs out of it.

  1. Type the numbers into L1.

    stat13enter5enter5enter7enter10enter

  2. Go back to the home screen with 2nd then mode (QUIT).

    2ndQUITmode

  3. Open the LIST math menu with 2nd then stat, then left. Choose mean( and give it L1.

    2ndLISTstat◀32ndL11)enter

  4. Do the same with median( (option 4).

    2ndLISTstat◀42ndL11)enter

You should seemean(L1) is 6 and median(L1) is 5.

Classic Graphing 84 key reference · Classic Graphing 84 manual

Classic CAS

Start on the main screen: Press home to open the Home menu (Calculator, Graphs, Settings, and more). Choose Calculator, or press esc to go back to the calculation page.

  1. Open the Statistics part of the menu and choose mean(.

    menu61

  2. Type the list in curly braces and close the bracket.

    shift{(3,5,5,7,10shift}))

  3. Press enter.

    enter

  4. Repeat with median( (menu, Statistics, option 2).

    menu62shift{(3,5,5,7,10shift}))enter

You should seeThe mean is 6 and the median is 5.

Classic CAS key reference · Classic CAS manual

Natural Scientific 991

Start on the main screen: Press MENU, then 1 (Calculate) to return to the main calculation screen. AC clears the line you are on.

  1. Open Statistics, choose 1-Variable and type the numbers.

    MENU613=5=5=7=10=AC

  2. Press OPTN and choose 1-Variable Calc. The first line is the mean.

    OPTN3

  3. Press the down arrow seven times to reach Med, the median.

    ▼▼▼▼▼▼▼

You should seeMed=5

Natural Scientific 991 key reference · Natural Scientific 991 manual

Natural Color Graphing

Start on the main screen: Press MENU then 1 to open Run-Matrix, the main calculation screen. Press EXIT to back out of a bar or screen, and SHIFT then EXIT (QUIT) to return to the app start.

  1. Enter the numbers in List 1 of the Stat mode.

    MENU23EXE5EXE5EXE7EXE10EXE

  2. Choose CALC (F2), then 1-VAR (F1). The mean is the first value.

    F2F1

  3. Scroll down to see Med, the median.

    ▼▼▼▼▼▼

You should seeMed=5

Natural Color Graphing key reference · Natural Color Graphing manual

RPN Scientific 15

Start on the main screen: There is no menu to leave. Press the back arrow to clear a number you are typing, or CLx (g then back arrow) to clear the X register.

  1. Clear the statistics memory first, so old data cannot sneak into the answer.

    fCLR ΣGSB

  2. Key in each number and press Σ+.

    3Σ+5Σ+5Σ+7Σ+10Σ+

  3. Press g then 0 for the mean.

    gx̄0

You should see6.0000

This model has no median key. Sort your numbers by hand and pick the middle one.

RPN Scientific 15 key reference · RPN Scientific 15 manual

RPN Power 48

Start on the main screen: Press ON to cancel what you are typing, then use the stack view. Open the MODE or VAR menu any time; the stack is always shown above the menu row.

  1. Type the list: left-shift then 8 opens curly braces. Separate numbers with the space key and press enter.

    ◀{ }83SPC5SPC5SPC7SPC10ENTER

  2. Add them up with right-shift then 3 (ΣLIST), then divide by the count, 5.

    ▶ΣLIST35÷

You should see1: 6

RPN Power 48 key reference · RPN Power 48 manual

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