<h2>
Answer:</h2>
The number of values in the upper quartile is : 10
<h2>
Step-by-step explanation:</h2>
We know that our data is divided into three quartiles:
1)
First quartile or lower quartile i.e. --
It is the median of the lower set of the data.
2)
Median or middle quartile i.e. --
Median is the central tendency of the data and it always exist in the middle of the data set.
3)
Upper quartile or Third quartile i.e. --
It is the median of the upper set of data.
Now, if there are even number of data points then the median exist in between two middle values and the upper and lower set of data takes half the data values.
Here we have number of data points as: 20
This means that the median of the data is between 10th and 11 th value i.e. 10.5
Hence, the lower set of data will have: 10 values
and the upper set of the data has: 10 values.