Answer:
The 80% confidence interval for the the population mean nitrate concentration is (0.144, 0.186).
Critical value t=1.318
Step-by-step explanation:
We have to calculate a 80% confidence interval for the mean.
The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.
The sample mean is M=0.165.
The sample size is N=25.
When σ is not known, s divided by the square root of N is used as an estimate of σM:

The degrees of freedom for this sample size are:

The t-value for a 80% confidence interval and 24 degrees of freedom is t=1.318.
The margin of error (MOE) can be calculated as:
Then, the lower and upper bounds of the confidence interval are:

The 80% confidence interval for the population mean nitrate concentration is (0.144, 0.186).
Answer: The missing statements are,
In first blank: ∠2≅∠1
In second blank: AC≅AC
In third blank: Reflexive
Step-by-step explanation:
Since, The hypotenuse angle theorem states that if the hypotenuse and an acute angle of one right triangle are congruent to the hypotenuse and an acute angle of another right triangle, then the two triangles are congruent to each other.
Here, given:
∠D and ∠B are right angles.
DC ║ AB
Prove: Δ ADC ≅ Δ CBA
Statement Reason
1.∠D and ∠B are right angles 1. Given
2. ∠2 ≅ ∠1 2. If lines are parallel then interior angles
are equal
3. AC≅AC 3. Reflexive
4.Δ ADC ≅ Δ CBA 4. Hypotenuse angle theorem
Answer:
x = -8
Step-by-step explanation:
Isolate the variable, x. Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS.
First, subtract 12 from both sides:
3x + 12 (-12) = -12 (-12)
3x = -12 - 12
3x = -24
Next, divide 3 from both sides:
(3x)/3 = (-24)/3
x = -24/3
x = -8
x = -8 is your answer.
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