[填空题]
A market research survey asked 200 teenagers xlwv8m5l-p65:e ts:q pii9mifor the number of minutes theq)yr/6n;dr m,wa k .z+ hiisiqru+ nzpx5;(b)y spend on their phones on a daily banrpi5zr)(q +;h.n,w b;qa /xdizry u k)sm +6isis. The results were recorded in the following box-and-whisker diagram.
1. Write down the median.
The following incomplete table shows the distribution of the responses from these 200 teenagers. minutes
2. Complete the table.
3. (1) Write down the mid-interval value for the $80 (2) Using the table, calculate an estimate for the mean number of minutes spent on phones daily by these 200 teenagers. ≈ minutes
The 200 teenages were chosen for the survey by randomly selecting student ID numbers in a school, using a random number generator.
4. Identify the sampling method used.
