I think u are supposed to divide like 9.70 divided by 5
<span>[3a2 + (–3a2)] + (–5ab + 8ab) + (b2 + 2b2)</span><span>
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The tree diagram for the probability is shown below
P(Clay|Positive) is read 'Probability of Clay given the result is Positive'.
This is a case of conditional probability.
The formula for conditional probability is given as
P(Clay|Positive) = P(Clay∩Positive) ÷ P(Positive)
P(Clay∩Positive) = 0.21×0.48 = 0.1008
P(Positive) = P(Rock∩Positive) + P(Clay∩Positive) + P(Sand∩Positive)
P(Positive) = (0.53×0.53) + (0.21×0.48) + (0.26×0.75)
P(Positive) = 0.2809 + 0.1008 + 0.195
P(Positive) = 0.5767
Hence,
P(Clay|Positive) = 0.1008÷0.5767 = 0.175 (rounded to 3 decimal place)
Angle 2 = 46°
Angle 3 = 180-46=134°
Ratios equivalent to 5:7
10:14
20:28
30:42
hope this helps :D