Respuesta :
Answer:
The students would be expected to choose rock be 80 or students choose hip hop be 160 or choose to country be 120.
Step-by-step explanation:
Given:
In a survey of 90 students 20 choose rock, 40 choose hip hop and 30 choose country.
Now, to find the students expected to choose hip hop or rock or country in a school of 360 students.
Let the number of students expected to choose rock be [tex]x.[/tex]
Let the number of students expected to choose hip hop be [tex]y.[/tex]
Let the number of students expected to choose country be [tex]z.[/tex]
Total number of students = 360.
Now, to get the number of students choosing hip hop or rock or country by using cross multiplication method:
In a survey of 90 students 20 choose rock.
So, 90 is equivalent to 20.
Thus, 360 is equivalent to [tex]x[/tex].
[tex]\frac{90}{20} =\frac{360}{x} \\\\By\ cross\ multiplying\ we\ get:\\\\90x=7200\\\\Dividing\ both\ sides\ by\ 90\ we\ get:\\\\x=80.[/tex]
Thus, the number of students expected to choose rock is 80.
Now,
In a survey of 90 students 40 choose hip hop.
So, 90 is equivalent to 40.
Thus, 360 is equivalent to [tex]y.[/tex]
[tex]\frac{90}{40} =\frac{360}{y} \\\\By\ cross\ multiplying\ we\ get:\\\\90y=14400\\\\Dividing\ both\ sides\ by\ 90\ we\ get:\\\\y=160.[/tex]
Therefore, 160 students expected to choose hip hop.
And,
In a survey of 90 students 30 choose country.
So, 90 is equivalent to 30.
Thus, 360 is equivalent to [tex]y.[/tex]
[tex]\frac{90}{30} =\frac{360}{z} \\\\By\ cross\ multiplying\ we\ get:\\\\90x=10800\\\\Dividing\ both\ sides\ by\ 90\ we\ get:\\\\x=120.[/tex]
Hence, 120 students expected to choose country.
Therefore, the students would be expected to choose rock be 80 or students choose hip hop be 160 or choose to country be 120.
