change my to by in "Trigger fruit quality checking from a sensor" (#326)

* Lesson 18 that to than - in Introduction

* change my to by

Co-authored-by: Jim Bennett <jim.bennett@microsoft.com>

4-manufacturing/lessons/4-trigger-fruit-detector/README.md

@@ -105,7 +105,7 @@ For the prototype, you will implement all of this on a single device. If you are
 
 ## Trigger fruit quality checking from a sensor
 
-The IoT device needs some kind of trigger to indicate when fruit is ready to be classified. One trigger for this would be to measure when the fruit is at the right location on the conveyor belt my measuring the distance to a sensor.
+The IoT device needs some kind of trigger to indicate when fruit is ready to be classified. One trigger for this would be to measure when the fruit is at the right location on the conveyor belt by measuring the distance to a sensor.
 
 ![Proximity sensors send laser beams to objects like bananas and time how long till the beam is bounced back](../../../images/proximity-sensor.png)