In this challenging assignment, you will create a VBA subroutine that will iterate through a set of files to bring in data from those files into a central spreadsheet. In the $$Week $3$ folder there is another folder $$Ralphie Reactor$($with files representing the output of the "Ralphie Reactor" $-$ named for the mascot here at CU Boulder!$).$ Within this folder are $24.$csv files, which are generated by a $($hypothetical$)$ bioreactor. You are in charge of quality assurance and wish for the temperature of the bioreactor to remain around $37\backslash$deg C$,$ the pH to stay around $5\mathrm{.}5,$ and the dissolved oxygen $($dO$2)$ concentration to remain around $50\%.$ The Ralphie Reactor automatically outputs the temperature, pH$,$ and dO$2$ concentration every hour, $24$ hours a day, and places the data into an hourly summary file. For example, here is what one might look like, at $3$:$00$ a$.$m$.($in the $$RalphieReactor$\_10-22-17\_300.$csv$$ file$)$:

As head of quality assurance, it is your job to summarize and analyze the results $($perhaps in graphical form$)$ once a day. Therefore, you set up a central file in which every morning you can import and analyze the data in those $24$ hourly summary files rather than doing this manually $($copying$/$pasting from those $24$ files each day$).$

You wish to automate the import of these $24$ hourly summary files into a main file $($the $$Assignment $3$ STARTER.xlsm$$ file$).$ The data in cells B$3$:B$6($column$)$ in each hourly summary file should be placed row$-$wise into the $$Assignment $3$ STARTER.xlsm$$ file, as shown below:

$*$This is the result after the subroutine has been executed.

Please see the $$Assignment $3$ screencast for a detailed demonstration of what you are trying to create in this assignment.

$**$HINT #$1$: To enable the user to input a range of cells using an input box, see the screencast "How to select a range using the input box method". You can adapt the code to enable the user in your subroutine to select cells B$3$:B$6($as requested by the grading file$)$ of the sheets that you import.$**$

$**$HINT #$2$: If you are following the method I used above in HINT #$1$ in the screencast referenced, UserRange is a range, and you need to convert that to a string in order to use later in your subroutine. You can use something like ImportRange $=$ UserRange.Address, where ImportRange is Dim'med as a String. Later on$,$ when you are iterating through your workbooks, you can refer to that range of each workbook by using Range$($ImportRange$)-$ be sure to use the full reference, e$.$g$.$ aWB.Sheets$(1).$Range$($ImportRange$).$Cells$(,).$

I have already placed three plots into this workbook, one each for temperature $($column B$),$ pH $($column C$),$ and dO$2$ concentration $($column D$).$ Therefore, this makes it easy each day to import the $24$ files and quickly analyze the data for any problems. It is likely that the time scales will be converted to decimals $($fraction of a day$),$ but that's okay.

What you need to do is create a properly working file that imports the data in the $24$ hourly summary files into your main file.

Helpful hint: To select multiple files in a folder, you can click on a file and hold down the Ctrl key while selecting additional files. Or$,$ Shift$-$click will select all files within two files. Better yet, click on one file in a folder then Ctrl$-$a to select all files in that folder!