Table:
|  | 2019 | 2018 | 2017 |
| --- | --- | --- | --- |
| Cost of revenue | $207 | $78 | $52 |
| Selling and marketing | 2,967 | 2,656 | 1,577 |
| Research and development | 2,013 | 1,801 | 1,028 |
| General and administrative | 4,450 | 4,415 | 2,821 |
| Stock-based compensation expense included in expenses | $9,637 | $8,950 | $5,478 |
Paragraphs:
Stock-based Compensation
The following table summarizes stock-based compensation expense related to RSUs, stock options, and ESPP shares for the fiscal years ended September 30, 2019, 2018, and 2017, which were allocated as follows (amounts shown in thousands):
Question:
What is the average expense of general and administrative from 2017 to 2019?
Answer: (4450+4415+2821)/3  = 3895.33