Answer:
x = - 1 ± 2i
Step-by-step explanation:
we can use the discriminant b² - 4ac to determine the nature of the roots
• If b² - 4ac > , roots are real and distinct
• If b² - 4ac = 0, roots are real and equal
• If b² - ac < 0, roots are not real
for x² + 2x + 5 = 0
with a = 1, b = 2 and c = 5, then
b² - 4ac = 2² - (4 × 1 × 5 ) = 4 - 20 = - 16
since b² - 4ac < 0 there are 2 complex roots
using the quadratic formula to calculate the roots
x = ( - 2 ±
) / 2
= (- 2 ± 4i ) / 2 = - 1 ± 2i
Answer:
step three
Step-by-step explanation:
-
s
s
s
d
d
d
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e
e
Step-by-step explanation:

Answer:
Step-by-step explanation:
We are given the following information in the question:
Mean, μ = 50
Standard Deviation, σ = 7
We are given that the distribution of random variable X is a bell shaped distribution that is a normal distribution.
Formula:
P(X greater than 34)
Calculation the value from standard normal z table, we have,
The attached image shows the normal curve.
Answer:
The 84% confidence interval for the population proportion that claim to always buckle up is (0.74, 0.80).
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the z-score that has a p-value of
.
They randomly survey 387 drivers and find that 298 claim to always buckle up.
This means that 
84% confidence level
So
, z is the value of Z that has a p-value of
, so
.
The lower limit of this interval is:

The upper limit of this interval is:

The 84% confidence interval for the population proportion that claim to always buckle up is (0.74, 0.80).