The probability that an interaction lasts longer than 4 minutes is 0.0062.
<h3>What is probability theory?</h3>
probability theory in mathematics focus on the analysis of random phenomena and this theory let us know that the outcome of a random event cannot be determined before it occurs.
z = (4 - 3)/.4
z = 1/.4
z = 2.5
0.0062
Hence The probability that an interaction lasts longer than 4 minutes is 0.0062.
We know that <span>Total soil--------> 3/4 ton </span><span>divide it by 8 (3/4)/8----> 3/(4*8)----> 3/32 ton----> 0.09375 ton----> multiply by 1000---> 93.75 kg
the answer is </span>93.75 kg f<span>or each bed</span>