What is the square root of -1?
1 answer:
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Answer:
Step-by-step explanation:
a.
The angles given are 62° and 90°.
We know sum of angles in any triangle is 180° so the third angle must be 180-90-62 = 28°
We can find the sides if we know trigonometric functions
sin28° = opp. side/ hypothenuse = CA/BA = 8/BA
BA = 8/sin 28° ≈ 17
tan62°= opp.side/adj.side= BC/AC = BC/8
BC = 8 · tan62° ≈ 15
b.
We are given 2 sides 8.5 and 6.5 and that one angle is right, so the triangle is a right triangle, therefore we can apply Pythagorean Theorem to find the third side.
6.5² +FD² = 8.5², subtract 6.5² from both sides
FD² = 8.5²- 6.5², square and combine like terms
FD² = 30, square-root both sides
FD = √30
FD ≈ 5.47722, round to the nearest tenth
FD ≈ 5.5
We can find the angles if we know trigonometric functions.
sin ∡D = FE/DE = 6.5/8.5
∡D = sin^-1 (6.5/8.5)
∡D ≈ 49.9°
cos ∡E = FE/DE = 6.5/8.5
∡E = cos^-1 (6.5/8.5)
∡E ≈ 40.1°
Answer:
b. 35.9, 39.1 ounces
Step-by-step explanation:
Previous concepts
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".
barX=37.465 represent the sample mean for the sample
population mean (variable of interest)
s=2.27 represent the sample standard deviation
n=10 represent the sample size
Confidence interval
The confidence interval for the mean is given by the following formula:
barX +- t*[(s)/(sqrt{n))] (1)
In order to calculate the critical value t we need to find first the degrees of freedom, given by:
df=n-1=10-1=9
Since the Confidence is 0.95 or 95%, the value of alpha=0.05 and \alpha/2 =0.025, and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,9)".And we see that t_(alpha/2)=2.26
Now we have everything in order to replace into formula (1):
37.465-2.26[(2.27)/(sqrt{10))]=35.9
37.465+2.26[(2.27)/(sqrt{10))]=39.1
So on this case the 95% confidence interval would be given by (35.9;39.1)