A survey of 120 college students is conducted and the results displayed below show that 80 students have a smartphone, 65 have a tablet, and 10 have neither. Fill in the empty table cells in the two-way frequency table.

Smartphone No Smartphone Total
Tablet 65
No Tablet 10
Total 80 120

What is the probability (rounded to the nearest whole percent) that a randomly selected college student has a tablet but not a smartphone?

Question

A survey of 120 college students is conducted and the results displayed below show that 80 students have a smartphone, 65 have a tablet, and 10 have neither. Fill in the empty table cells in the two-way frequency table.

Smartphone No Smartphone Total
Tablet 65
No Tablet 10 
Total 80 120

What is the probability (rounded to the nearest whole percent) that a randomly selected college student has a tablet but not a smartphone?

Mercury · Answer

to fill out the table, remember that the outer values are the sums of the columns/rows.

ex:

|dw:1588910332231:dw|

"randomly selected college student has a tablet but not a smartphone"

so you should find (college students who have a tablet and no smartphone) / (total # of students)