Answer:
0.8224
Step-by-step explanation:
Data
- standard deviation, sd: $10
- first value of interest, x1: $63
- second value of interest, x2: $90
z-score for x1:
z1 = (x1 - mean)/sd = (63 - 76)/10 = -1.3
z-score for x2:
z2 = (x2 - mean)/sd = (90 - 76)/10 = 1.4
The proportion of wrist watch prices are between $63 and $90 is:
P(z1 < z < z2) = P(z < 1.4) - P(z < -1.3)
P(z < 1.4) = 0.9192 (see first picture attached)
P(z < -1.3) = 0.0968 (see second picture attached)
P(z1 < z < z2) = 0.9192 - 0.0968 = 0.8224
Answer: I do not age
Step-by-step explanation: I have magical Phoenix powers and i drink a lot of ageless potions
<span>(y + 9)(y - 2) = 0 would be the correct answer .</span>
Answer:
Both the boats will closet together at 2:21:36 pm.
Step-by-step explanation:
Given that - At 2 pm boat 1 leaves dock and heads south and boat 2 heads east towards the dock. Assume the dock is at origin (0,0).
Speed of boat 1 is 20 km/h so the position of boat 1 at any time (0,-20t),
Formula : d=v*t
at 2 pm boat 2 was 15 km due west of the dock because it took the boat 1 hour to reach there at 15 km/h, so the position of boat 2 at that time was (-15,0)
the position of boat 2 is changing towards east, so the position of boat 2 at any time (-15+15t,0)
Formula : D=
⇒ 
Now let 
∵ 
⇒ t= 450/1250
⇒ t= .36 hours
⇒ = 21 min 36 sec
Since F"(t)=0,
∴ This time gives us a minimum.
Thus, The two boats will closet together at 2:21:36 pm.
