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:
Melissa = D
Victor = C
Step-by-step explanation:
Mowing 4 lawns in 6 hours gives a mowing rate of 6/4 = 1.5 hours per lawn.
To mow 9 lawns, you need 1.5*9 = 13.5 hours.
The answer is B.
Answer: he will have $12720 after 15 years
Step-by-step explanation:
We would apply the formula for determining compound interest which is expressed as
A = P(1 + r/n)^nt
Where
A = total amount in the account at the end of t years
r represents the interest rate.
n represents the periodic interval at which it was compounded.
P represents the principal or initial amount deposited
From the information given,
P = $8000
r = 3.1% = 3.1/100 = 0.031
n = 12 because it was compounded 12 times in a year.
t = 15 years
Therefore,
A = 8000(1 + 0.031/12)^12 × 15
A = 8000(1 + 0.00258)^180
A = 8000(1.00258)^180
A = $12720
