91Ó°ÊÓ

It is given that to investigate children's birth days Mrs. McDonald and her class

selected an SRS of $73$people born since $1993$.

it is found that of these people, $24$were born on Friday, Saturday, or Sunday.

to check that these data provide strong evidence that fewer than $43\%\left(\raisebox{1ex}{$3$}\!\left/ \!\raisebox{-1ex}{$7$}\right.\right)$of

people born since $1993$were born on Friday, Saturday, or Sunday, $100$simulated SRSs

were selected.

the below graph shows the data of people born on Friday, Saturday, or Sunday in a simulated SRS of $73$people, assuming that each person had a $43\%$chance of being born on one of these three days.

a. we need to find how the graph shows the concept of sampling variability

Each dot in the above graph shows a random sample of $73$people

It is found that each of the samples does not have the same no. of people who were born on Friday, Saturday, or Sunday and this shows that there is sampling variability present among the different samples and the no. of people varies from $22$to$40$.

It is given that to investigate children's birth days Mrs. McDonald and her class

selected an SRS of $73$people born since $1993$.

it is found that of these people, $24$were born on Friday, Saturday, or Sunday.

to check that these data provide strong evidence that fewer than $43\%\left(\raisebox{1ex}{$3$}\!\left/ \!\raisebox{-1ex}{$7$}\right.\right)$of

people born since$1993$were born on Friday, Saturday, or Sunday, $100$simulated SRSs

were selected.

the below graph shows the data of people born on Friday, Saturday, or Sunday in a simulated SRS of $73$people, assuming that each person had a $43\%$chance of being born on one of these three days.

b. we need to find is there convincing evidence that fewer than $43\%$of people born since $1993$were born on Friday, Saturday, or Sunday.

From the data

$43\%$of the people is $43\%×73=.43×73=31.39≈31$

From the graph, we can say that there are $8$dots at $31$and this implies that $31$people were born on Friday, Saturday, or Sunday. but this does not show that fewer than $43\%$of people born since $1993$were born on Friday, Saturday, or Sunday, and this implies that there is no convincing evidence that fewer than $43\%$of people born since $1993$were born on Friday, Saturday or Sunday.