Terry has about 20 keys which number could be the exact number of keys that terry has
1 answer:
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A suitable probability calculator will tell you that probabilty is about 25.9%.
_____
The normalcdf function on this calculator gives an area between a lower and upper limit. If the upper limit is more than about 8 standard deviations above the mean, the 10th decimal place is unaffected. Since the standard deviation here is about 5, we need to have an upper limit that is about 40 above the mean of about 30. We have chosen 80 as a nice round number and to give a little more margin.
Answer:
The distance between them after 30 minutes is 6.5 km.
Step-by-step explanation:
Speed =
Sarah's speed = 6 km/hr = 1.6667 m/s
Emily's speed = 10 km/hr = 2.7778 m/s
The measure of angle between their bearings =
After 30 minutes (1800 seconds);
distance = speed x time
Sarah would have covered a distance = 1.6667 x 1800
= 3000 m
= 3 km
Emily would have covered a distance = 2.7778 x 1800
= 5000 m
= 5 km
The distance between them, a, can be determined by applying the cosine rule;
=
+
- 2bcCos A
= +
-2(5000 x 3000) Cos 105
= +
-2(5000 x 3000) x (-0.2588)
= 2.5 x + 9 x
+ 7764000
= 41764000
a =
= 6462.5073
a = 6462.5 m
The distance between them after 30 minutes is 6.5 km.