You have to use your standard normal table (or calculator) for these. The area under the curve should be 1, a z-value corresponds to the probability and is area to the left of that z.
a. A simple reverse lookup of 0.9750. z=1.96
b. Total area up to z would be 0.5+0.4750, so reverse look up 0.9750 and find z=1.96
c. A simple reverse lookup. z=0.61
d. Area to the left of z would b 1-0.1314, so lookup 0.8686 and find z=1.12
e. A simple reverse lookup. z=0.44
f. Just invert the area: 1-0.33 = 0.67 and reverse lookup: z=0.44
Answer:
z ≤ 8
Step-by-step explanation:
-9z ≥ -72
Isolate the variable, z. Treat the ≥ as a equal sign, what you do to one side, you do to the other. Divide -9 from both sides. Note that when you divide a negative number, you will flip the sign:
(-9z)/-9 ≥ (-72)/-9
z ≤ (-72)/(-9)
z ≤ 8
z ≤ 8 is your answer.
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So speed = distance divided by time, therefore 70 miles divided by 35 minutes = 120mph. The speedboats speed was 120mph.
Hope this helps
Answer:
<em>3 seconds</em>
Step-by-step explanation:
Given the height modelled by the function
h(t) = -16t² + 16t + 96
The hit the water at h(t) = 0
0 = -16t² + 16t + 96
Divide through b y -16
0 = t² - t - 6
t² - t - 6 = 0
t² - 3t+2t - 6 = 0
t(t-3)+2(t-3) = 0
t+ 2 = 0 and t - 3 = 0
t = -2 secs and t = 3secs
Since t can't be negative, hence;
t = 3 secs
<em>hence it will take 3 seconds until Devon hit the water</em>
Answer:
36 in over 2
Step-by-step explanation:
