Answer:
a) 279 b)254
Step-by-step explanation:
Mean = 269 days
standard deviation = 8 days
let n be the pregnancy lenght.
using normal distribution formula
z = (n – mean)/ standard deviation
n = z * standard deviation + mean
Now, z values for the top 12% has to be found using a z table.
The top 12% means 88% of area under the curve. In this case z = 1,176
n = 1,176 * 8 + 269
n = 278.4 = 279
The bottom 3% means 97% of area under the curve. In this case z = -1,882
n = -1,882 * 8 + 269
n = 253.94 = 254
Answer: 11) 1/3
12)1/4
13) Likely
Step-by-step explanation:
<span>1st train DATA:
rate = 50 mph ; time = x hrs ; distance = rt = 50x miles
2nd train DATA:
rate = 55 mph ; time = (x-(1/2)) hrs ; distance = rt = 55(x-(1/2)) miles
Equation:
distance = distance
50x = 55(x-(1/2)
50x = 55x - (55/2)
-5x = -55/2
x = 11/2
x = 5 1/2 hrs (time at which the 2nd train overtakes the 1st train)
Hope this helps!</span>
Answer:
a or b
Step-by-step explanation:
if I did the math right it's a but I tried another way and got b, so I'm sorry if that was no help at all
