Answer:
The sum of reciprocals is 2/3.
You don't need complex numbers to solve this, but if you try to find a and b you will need complex numbers.
Step-by-step explanation:
a+b = 2
a*b = 3
1/a + 1/b = x
(a*b)*(1/a + 1/b) = (a*b)x
b + a = (a*b)(x)
2 = 3x
x = 2/3
b = 2 - a
a*(2 - a) = 3
-a^2 + 2a = 3
-a^2 + 2a - 3 = 0
a^2 - 2a + 3 = 0
let's solve the quadratic equation
a^2 - 2a + 3 = a^2 - 2a + 1 + 2 = (a - 1)^2 + 2 = 0
(a - 1)^2 = -2
these options correspond to a and b from the original question.
The value of three in 6,300 is 3,000 because it is in the thousands place. The three in 530 is in the hundreds place making the value of three 300. Hope that this helps you :D
Answer:
a)0.6192
b)0.7422
c)0.8904
d)at least 151 sample is needed for 95% probability that sample mean falls within 8$ of the population mean.
Step-by-step explanation:
Let z(p) be the z-statistic of the probability that the mean price for a sample is within the margin of error. Then
z(p)=
where
- Me is the margin of error from the mean
- s is the standard deviation of the population
a.
z(p)=
≈ 0.8764
by looking z-table corresponding p value is 1-0.3808=0.6192
b.
z(p)=
≈ 1.1314
by looking z-table corresponding p value is 1-0.2578=0.7422
c.
z(p)=
≈ 1.6
by looking z-table corresponding p value is 1-0.1096=0.8904
d.
Minimum required sample size for 0.95 probability is
N≥
where
- z is the corresponding z-score in 95% probability (1.96)
- s is the standard deviation (50)
- ME is the margin of error (8)
then N≥
≈150.6
Thus at least 151 sample is needed for 95% probability that sample mean falls within 8$ of the population mean.
The dad had 6 more hours remaining to drive
