\textbf{44--} The position--time graph of a particle moving along the $x$-axis with constant acceleration is shown below. What is the magnitude of the average speed of the particle in the first 7 seconds?
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\textit{[Figure: position-time graph with x(m) axis showing value 24 at top, curve passing through origin, reaching a minimum near t=2, then rising to 24 at t=7; t(s) axis shows values 2 and 7]}
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(1) $\dfrac{25}{8}$
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(2) $\dfrac{25}{7}$
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(3) $\dfrac{23}{8}$
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(4) $\dfrac{23}{7}$
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