I need help in answer questions #$8,9,$ and #$6$b$.$

The images shows sample worksheet I have to fill out. The answers were taken from the given Account Receivable data. I need to fill out the highlighted cells. Below is an explanation of how I got to my answers. Let me know if my actions are correct.

$3$a$.$ Total Account balance

Number of Items: $1,000[$Counted all the account receivable amount$]$

Amount $7,870,003[$Calculated the sum of all the given account receivable amount$]$

$3$b$.$ Individually significant dollar item

As per planning memo, ISI is planning materiality $(75,000)$ divided by $3$ which is $25,000$

Number of Items: $92[$Counted all the account receivable that is greater than $25,000]$

Amount: $3,969,910[$Calculated the sum of all account receivable greater than $25,000$

$3$c$.$ Unusual items

In this case, any amount that is negative is considered unusual items

Number of Items: $20[$Counted all negative account receivable$]$

Amount: $-188,907[$Calculated the sum of all account receivable that has a negative amount$]$

$3$d$.$ Remaining balance

Number of Items: $888(1,000-92+20)$

Amount: $4,088,999(7,870,003-3,969,910+(-188,907)$

$3$e$.$ Tolerable misstatement

$75,000[$The same as planning materiality because given powerpoint says ISI is calculated from tolerable misstatement divided by $3$ but planning memo used planning materiality instead of tolerable misstatement. I am assuming that planning materiality is being interchanged for tolerable misstatement. No guidance given to compute tolerable misstatement in planning memo.

$5.$ Tick sampling box

Since $3$e is greater than $3$d$,$ further actions is needed. In this case I chose sampling.

$6$a$.$ same as $3$a

$6$b$.$ I don$$t know the answer for this one. They said to use a lower amount of individually significant dollar item. What is the lower amount? Planning memo did not specify how to find this.

$6$c$.$ same as $3$c

$6$d$.$ same as $3$d

$6$e$.$ same as $3$e$.$

Not sure what to put for questions #$6$b$,8$ and $9.$ Please help.