Assist with HW

Use the following information to answer questions 4-6:

Internal Revenue Services (IRS) selects taxpayer files for audit if their profile matches certain criteria. The Following sample is taken from taxpayers who were audited for tax year 2019:

Frequency	Taxable Income($1000s)
2	20 to under 40
5	40 to under 60
22	60 to under 80
25	80 to under 100
15	100 to under 120
10	120 to under 140
6	140 to under 160
5	160 to under 180

4. What is the cumulative relative frequency of taxpayers who were audited and their taxable income was less than $120,000?

5. What was the approximate average taxable income of taxpayers in this sample?

6. What is the approximate standard deviation of taxable income in this sample, rounded to the nearest dollar?