Solve for r 5(r-10)=-51
2 answers:
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Answer:
x = - 3 is extraneous
Step-by-step explanation:
Given
- 1 = x ( add 1 to both sides )
= x + 1 ( square both sides )
x + 7 = (x + 1)² ← distribute right side
x + 7 = x² + 2x + 1 ( subtract x + 7 from both sides )
0 = x² + x - 6 ← in standard form
0 = (x + 3)(x - 2) ← in factored form
Equate each factor to zero and solve for x
x + 3 = 0 ⇒ x = - 3
x - 2 = 0 ⇒ x = 2
As a check
Substitute these values into the equation and if both sides are equal then they are the solutions.
x = - 3 : - 1 =
- 1 = 2 - 1 = 1 ≠ - 3
x = 2 : - 1 =
- 1 = 3 - 1 = 2
x = 2 is a solution and x = - 3 is extraneous
Answer:
Null hypothesis:
Alternative hypothesis:
Step-by-step explanation:
1) Previous concepts and data given
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
A right tailed test (sometimes called an upper test) is when the alternative hypothesis statement contains a greater than (>) symbol.
represent the sample mean
s represent the sample standard deviation
n represent the sample selected
significance level
State the null and alternative hypotheses.
We need to conduct a hypothesis in order to check if the mean for fluorescent bulbs is no more than 3.24 mg of mercury, the system of hypothesis would be:
Null hypothesis:
Alternative hypothesis:
IIf we know the population deviation we can apply a z test to compare the actual mean to the reference value, and the statistic is given by:
(1)
z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".