For this Q:
mean=31
st.dev.=0.8
x=32
Calculate z-score:
z=(x-m)/s = (32-31)/0.8=1.25
This z-score value corresponding to the probability of 0.8944
<span />
Answer:
5 units
Step-by-step explanation:
The graph helps you measure it
Let
x--------> <span>the speed of the boat in mph
we know that
</span>going upstream the speed is x-7
<span>going downstream the speed is x+7
</span>
let the distance be d
<span>time to go upstream = d/(x-7) </span>
<span>time to go downstream = d/(x+7)
</span>
time going upstream is 3 times going downstream
so
<span>3d/(x+7) = d/(x-7) </span>
<span>divide by d </span>
<span>3/(x+7) = 1/(x-7) </span>
<span>3x-21 = x+7 </span>
<span>2x = 28 </span>
<span>x = 14
</span>
the answer is
<span>the speed of the boat in still water is 14 mph</span>
Start at -8 move to the left 8 more times,. You get -16.
