Analyze the sentiment expressed in the tweet. Is it positive, negative, or neutral? Explain the sentiment in relation to the stock mentioned.
TWEET: ""Excellent way for my son to prepare for exam! He only missed 2 on the test! Thank you" @Groupon #HappyCustomer

" STOCK: Groupon DATE: 11/09/2018
Sentiment: (Provide sentiment here)
Explanation: The tweet sentiment is related to the stock mentioned, and it's important to interpret the context. The LSTM polarity score is 1 and the TextBlob polarity score is 1.0.