Histogram practice worksheet with blank graphs for analyzing age and car age data.

I will solve the problem presented in the image, which involves answering questions based on three different histograms. I'll go through each histogram and its corresponding questions one by one.

First Histogram: People's Ages at a Mall

The first histogram shows the age distribution of people surveyed at a mall.

Questions:
1. How many people were 30 years or older?
2. How many people were under 40?
3. What percentage of people were under 20?
4. What percentage of people were between 20 and 30?
5. Estimate the mean age of the people surveyed.

Analysis:
- The x-axis represents age groups: 0-10, 10-20, 20-30, 30-40, 40-50.
- The y-axis represents frequency (number of people).

From the histogram:
- 0-10: approximately 5 people
- 10-20: approximately 10 people
- 20-30: approximately 15 people
- 30-40: approximately 20 people
- 40-50: approximately 10 people

Total number of people surveyed = 5 + 10 + 15 + 20 + 10 = 60 people

Now let's answer the questions:

1. How many people were 30 years or older?
- 30-40: 20 people
- 40-50: 10 people
- Total = 20 + 10 = 30 people

2. How many people were under 40?
- 0-10: 5 people
- 10-20: 10 people
- 20-30: 15 people
- 30-40: 20 people
- Total = 5 + 10 + 15 + 20 = 50 people

3. What percentage of people were under 20?
- 0-10: 5 people
- 10-20: 10 people
- Total under 20 = 5 + 10 = 15 people
- Percentage = (15 / 60) * 100 = 25%

4. What percentage of people were between 20 and 30?
- 20-30: 15 people
- Percentage = (15 / 60) * 100 = 25%

5. Estimate the mean age of the people surveyed.
- To estimate the mean, we can use the midpoint of each age group multiplied by the frequency, then divide by the total number of people.
- Midpoints: 5 (for 0-10), 15 (for 10-20), 25 (for 20-30), 35 (for 30-40), 45 (for 40-50)
- Mean = [(5*5) + (15*10) + (25*15) + (35*20) + (45*10)] / 60
- Mean = [25 + 150 + 375 + 700 + 450] / 60
- Mean = 1700 / 60 ≈ 28.33 years

Second Histogram: Car Ages in Households

The second histogram shows the age of primary family cars for 40 households.

Questions:
1. How many households were surveyed?
2. What percentage of households have cars that are less than 5 years old?
3. What percentage of households have cars that are 5 years or more?
4. How many households had cars between 5 and 10 years old?
5. What percentage of households had cars that were 10 years or older?

Analysis:
- The x-axis represents car age in years: 0-5, 5-10, 10-15, 15-20, 20-25.
- The y-axis represents frequency (number of households).

From the histogram:
- 0-5: approximately 10 households
- 5-10: approximately 15 households
- 10-15: approximately 10 households
- 15-20: approximately 5 households
- 20-25: approximately 0 households

Total number of households surveyed = 10 + 15 + 10 + 5 + 0 = 40 households (as stated in the question)

Now let's answer the questions:

1. How many households were surveyed?
- 40 households (given in the question)

2. What percentage of households have cars that are less than 5 years old?
- 0-5: 10 households
- Percentage = (10 / 40) * 100 = 25%

3. What percentage of households have cars that are 5 years or more?
- 5-10: 15 households
- 10-15: 10 households
- 15-20: 5 households
- 20-25: 0 households
- Total = 15 + 10 + 5 + 0 = 30 households
- Percentage = (30 / 40) * 100 = 75%

4. How many households had cars between 5 and 10 years old?
- 5-10: 15 households

5. What percentage of households had cars that were 10 years or older?
- 10-15: 10 households
- 15-20: 5 households
- 20-25: 0 households
- Total = 10 + 5 + 0 = 15 households
- Percentage = (15 / 40) * 100 = 37.5%

Third Histogram: Girls' Heights

The third part asks to create a histogram from given data.

Data:
- Heights measured in inches: 60", 61", 63", 65", 66", 67", 67", 68", 69", 70"

To create a histogram, we need to group the data into intervals. A reasonable interval might be 2 inches wide.

Intervals:
- 60-61: 60", 61" → 2 girls
- 62-63: 63" → 1 girl
- 64-65: 65" → 1 girl
- 66-67: 66", 67", 67" → 3 girls
- 68-69: 68", 69" → 2 girls
- 70-71: 70" → 1 girl

Histogram:
- X-axis: Height intervals (60-61, 62-63, 64-65, 66-67, 68-69, 70-71)
- Y-axis: Frequency (number of girls)

The histogram would show bars with heights corresponding to the frequencies: 2, 1, 1, 3, 2, 1.

Summary of Answers:

First Histogram (People's Ages at a Mall):
1. 30 people were 30 years or older.
2. 50 people were under 40.
3. 25% of people were under 20.
4. 25% of people were between 20 and 30.
5. The estimated mean age is approximately 28.33 years.

Second Histogram (Car Ages in Households):
1. 40 households were surveyed.
2. 25% of households have cars that are less than 5 years old.
3. 75% of households have cars that are 5 years or more.
4. 15 households had cars between 5 and 10 years old.
5. 37.5% of households had cars that were 10 years or older.

Third Part (Girls' Heights):
- Create a histogram with intervals 60-61, 62-63, 64-65, 66-67, 68-69, 70-71 and corresponding frequencies 2, 1, 1, 3, 2, 1.

This completes the solution to the problem presented in the image.