Asample of 161children was selected from fourth and fifth graders at elementary schools in philadelphia. in addition to recording the grade level, the researchers determined whether each child had a previously undetected reading disability. sixty-six children were diagnosed with a reading disability. of these children, 32 were fourth graders and 34 were fifth graders. similarly, of the 95 children with normal reading achievement, 55 were fourth graders and 40 were fifth graders.
a. identify the two qualitative variables (and corresponding levels) measured in the study.
b. from the information provided, form a contigency table.
c. assuming that the two variables are independent, calculate the expected cell counts.

Step-by-step explanation:

Given that a sample of 161children was selected from fourth and fifth graders at elementary schools in Philadelphia. In addition to recording the grade level, the researchers determined whether each child had a previously undetected reading disability

a) The two qualitative variables are disability and not having disability and secondly the grades of children

b) Contingency table:

Grade                  4                5                      Total

Normal read.       32              34                        66

Not normal read.  23                6                        29  

Total                      55             40                         95

H0: Reading disability is independent of grade.

Ha: There is association between the two

c)  45Total

Nor read38.2105263227.7894736866

Not norm16.7894736812.2105263229

Expected cells are obtained using the formula

row total*col total/grand total

$53.50

step-by-step explanation:

you have to subtract the amount of money chuck earned ($72.50) by the cost of the gas for the mower ($11.25) and the new string for the trimmer he bought ($7.75).

72.50-11.25=61.25

and then subtract $61.25 by the second thing he bought (the new string for the trimmer)

61.25-7.75=53.5

so in total it's $53.50 (53 dollars and 50 cents)