*Question E7F08:
What is the function of decimation?*  

*Correct Answer is  B: Reducing the effective sample rate by removing samples*  

### AI Response: (may contain errors)  

Decimation is a process used in digital signal processing (DSP) to reduce the effective sample rate of a signal by removing some of the samples. This is useful when you want to decrease the amount of data to process or when you need to match the sample rate to a lower rate required by a subsequent stage in the processing chain.

### Explanation of the Correct Answer:
- **Correct Answer (B): Reducing the effective sample rate by removing samples**  
  Decimation involves taking a high sample rate signal and reducing its sample rate by a factor, often called the decimation factor. For example, if you have a signal sampled at 1000 samples per second and you decimate by a factor of 2, the new sample rate will be 500 samples per second. This is achieved by keeping every second sample and discarding the others.

### Why the Other Choices are Incorrect:
- **Choice A: Converting data to binary-coded decimal form**  
  This choice describes a data conversion process, not related to changing the sample rate. Binary-coded decimal (BCD) is a way of representing numbers where each digit is stored as a separate binary value.

- **Choice C: Attenuating the signal**  
  Attenuation refers to reducing the amplitude or power of a signal, not its sample rate. Decimation specifically deals with reducing the number of samples, not the signal's strength.

- **Choice D: Removing unnecessary significant digits**  
  This choice refers to numerical precision and is unrelated to sample rate reduction. Decimation is about reducing the number of samples, not altering the precision of the data.

### Useful Formula:
- If you have a signal with an original sample rate $f_s$ and you decimate by a factor $D$, the new sample rate $f_{new}$ is given by:  
  $$f_{new} = \frac{f_s}{D}$$

This formula helps you calculate the new sample rate after decimation, which is crucial for understanding how the process affects the signal.