Question

34 a school bus was used for a field trip. which situation about the school bus most likely yields data without variability? a) the number of seats on the school bus b) the speed of the school bus c) the temperature inside the school bus d) the amount of fuel in the fuel tank of the school bus 35 the dot - plot shows the number of games a middle school basketball team won in each of the past 15 seasons. what is the mean of the data? each ● means 1 season.

Explanation:

34.

Step1: Analyze variability concept

Variability means the values can change.

Step2: Evaluate option A

The number of seats on a school - bus is fixed. It doesn't change during the field - trip, so there is no variability.

Step3: Evaluate option B

The speed of the school bus can change during the trip due to traffic, road conditions, etc., so it has variability.

Step4: Evaluate option C

The temperature inside the school bus can change depending on the weather outside, the use of the air - conditioner or heater, so it has variability.

Step5: Evaluate option D

The amount of fuel in the fuel tank of the school bus decreases as the bus travels, so it has variability.

Step1: Recall mean formula

The mean $\bar{x}=\frac{\sum_{i = 1}^{n}x_{i}f_{i}}{\sum_{i = 1}^{n}f_{i}}$, where $x_{i}$ is the data - value and $f_{i}$ is the frequency. Here, $\sum_{i = 1}^{n}f_{i}=15$ (total number of seasons).

Step2: Calculate the sum of the products

For $x = 2$, $f = 1$; for $x = 4$, $f = 1$; for $x = 6$, $f = 2$; for $x = 7$, $f = 1$; for $x = 8$, $f = 2$; for $x = 9$, $f = 3$; for $x = 10$, $f = 3$; for $x = 11$, $f = 2$.
$\sum_{i = 1}^{n}x_{i}f_{i}=2\times1 + 4\times1+6\times2 + 7\times1+8\times2+9\times3+10\times3+11\times2$
$=2 + 4+12 + 7+16+27+30+22$
$=110$.

Step3: Calculate the mean

$\bar{x}=\frac{110}{15}=\frac{22}{3}\approx7.33$.

Answer:

A. The number of seats on the school bus

35.