I would like to create a new column called "Standard" as a composite of the results from three tests (three different columns in my dataset).

* If all three tests are positive, the standard will be called "Strong".
* If two out three tests are positive, the standard will be called "Medium"
* If only one test is positive, the standard will be called "Scanty"
* And if none of the tests is positive, the standard will be called "Failed".

I have about 100 records in the dataset and I would like to find a way to do this in R without having to proceed manually. I haven't tried anything because I don't know what to try and I am new to R. Any help or hint will be really appreciated. Thanks.

The dataset looks like this:

```
     ID   Test_1   Test_2   Test_3
     1   positive positive positive
     2   positive negative positive
     3   positive positive negative
     4   negative negative positive
     5   negative positive negative
     6   negative negative negative
     7   positive negative negative

```

Below is what I am expecting the final dataset to look like:

```
     ID   Test_1   Test_2   Test_3   Standard
     1   positive positive positive   Strong
     2   positive negative positive   Medium
     3   positive positive negative   Medium
     4   negative negative positive   Scanty
     5   negative positive negative   Scanty
     6   negative negative negative   Failed
     7   positive negative negative   Scanty

```