Question

for exercises 27–34, classify each variable as discrete or continuous. 27. number of street corner mailboxes in the city of philadelphia. 28. relative humidity levels in operating rooms at local hospitals. 29. number of bananas in a bunch at several local supermarkets. 30. ages of women when they were first married. 31. weights of the backpacks of first - graders on a school bus. 32. number of students each day who make appointments with a math tutor at a local college. 33. duration of marriages in america (in years). 34. ages of children in a preschool. for exercises 35–38, give the boundaries of each value. 35. 56 yards. 36. 105.4 miles. 37. 72.6 tons. 38. 9.54 millimeters.

Explanation:

Step1: Recall discrete - continuous variable concept

Discrete variables are countable and have distinct values. Continuous variables can take any value in an interval.

Step2: Analyze 35 - 38 for boundaries

For a measured value $x$, the lower boundary is $x - 0.5$ of the smallest unit and the upper boundary is $x+ 0.5$ of the smallest unit.

For 35:

The value is 56 yards. The smallest unit is 1 yard.
Lower boundary: $56 - 0.5=55.5$ yards
Upper boundary: $56 + 0.5 = 56.5$ yards

For 36:

The value is 105.4 miles. The smallest unit is 0.1 mile.
Lower boundary: $105.4-0.05 = 105.35$ miles
Upper boundary: $105.4 + 0.05=105.45$ miles

For 37:

The value is 72.6 tons. The smallest unit is 0.1 ton.
Lower boundary: $72.6-0.05 = 72.55$ tons
Upper boundary: $72.6 + 0.05=72.65$ tons

For 38:

The value is 9.54 millimeters. The smallest unit is 0.01 millimeter.
Lower boundary: $9.54 - 0.005=9.535$ millimeters
Upper boundary: $9.54+0.005 = 9.545$ millimeters

Answer:

1. Lower boundary: 55.5 yards, Upper boundary: 56.5 yards
2. Lower boundary: 105.35 miles, Upper boundary: 105.45 miles
3. Lower boundary: 72.55 tons, Upper boundary: 72.65 tons
4. Lower boundary: 9.535 millimeters, Upper boundary: 9.545 millimeters