Question

1. Describe the difference between inferential and descriptive statistics.

2. Why don’t we just measure populations? Why do we use samples to infer about populations?

3. Ten people were asked how many siblings they have. Below is the data:

2, 4, 1, 2, 1, 3, 5, 0, 1, 3, 0

4. Create a frequency distribution table.

5. Add on a cumulative frequency column and compute the cumulative frequencies.

6. Add on a relative frequency column and compute the relative frequencies.

Answer 1

It is true that measuring samples rather than the whole population is ethically incorrect but when time and money is limited and human resources are also limited, sampling is a wonderful option. And the reason is that for most purposes we can obtain suitable accuracy quickly and inexpensively on information gained from a sample.

So, why would we study the entire population when a scientifically drawn sample, provides accuracy in representing our population of interest. Assessing all individuals may be impossible, impractical, expensive or even inaccurate.

Now, here is some points which says why we shouldn't measure the whole population.

1. It needs a lot of money

2. It needs a lot of time and human resources

3. The chance of having error is very high when we measure the whole population.

For the next problem note that in the question it is said that then response was from ten people but 11 data point is given , so I'm doing the solution considering 11 response. For the solution see the following image