Question

a random sample of students was surveyed and asked to list their grade level and whether or not they have a pet. results are shown in the table below, but some values are missing. fill in the missing values.

pets survey

	pets	no pets	total
7th grade
8th grade	16		30
total	49		105

Explanation:

Step1: Find 6th - grade pets number

Use the formula: \( \text{Pets in 6th grade}=\text{Total in 6th grade}-\text{No - pets in 6th grade}\).
So, \(39 - 16=23\).

Step2: Find 8th - grade no - pets number

Use the formula: \( \text{No - pets in 8th grade}=\text{Total in 8th grade}-\text{Pets in 8th grade}\).
So, \(30 - 16 = 14\).

Step3: Find total no - pets number

Use the formula: \( \text{Total no - pets}=\text{Total}-\text{Total pets}\).
So, \(105 - 49=56\).

Step4: Find 7th - grade pets number

Use the formula: \( \text{Pets in 7th grade}=\text{Total pets}-\text{Pets in 6th grade}-\text{Pets in 8th grade}\).
So, \(49-(23 + 16)=49 - 39=10\).

Step5: Find 7th - grade no - pets number

Use the formula: \( \text{No - pets in 7th grade}=\text{Total no - pets}-\text{No - pets in 6th grade}-\text{No - pets in 8th grade}\).
So, \(56-(16 + 14)=56 - 30=26\).

Step6: Find 7th - grade total number

Use the formula: \( \text{Total in 7th grade}=\text{Pets in 7th grade}+\text{No - pets in 7th grade}\).
So, \(10+26 = 36\).

Answer:

6th - grade pets: \(23\); 7th - grade pets: \(10\); 7th - grade no - pets: \(26\); 7th - grade total: \(36\); 8th - grade no - pets: \(14\); Total no - pets: \(56\)