Answer:
Critical value t-score=2.701.
Step-by-step explanation:
When we calculate a confidence interval with an unknown population standard deviation, we estimate it from the sample standard deviation and use the t-score instead of the z-score.
The critical value for t depends on the level of confidence and the degrees of freedom.
If the sample size is 42, the degrees of freedom are:
For a confidence level of 99% and 41 degrees of freedom, the critical value of t is t=2.701.
Answer:
distance: 320.624 miles
direction: 43.576°
Step-by-step explanation:
The speed and direction can be found by adding the given vectors.
... 320∠40° + 20∠130°
... = (320·cos(40°), 320·sin(40°)) + (20·cos(130°), 20·sin(130°))
... = (245.134, 205.692) +(-12.856, 15.321) = (232.278, 221.013)
The magnitude of the vector with these components is found using the Pythagorean theorem. The direction is found using the arctangent function.
... = √(232.278² +221.013²)∠arctan(221.013/232.278)
... = 320.624∠43.576°
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A suitable vector or graphing calculator can do this easily. In the screenshot of a TI-84 app below, the variable D has the value π/180. The display mode is set to degrees.
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<em>Comment on coordinate systems</em>
Navigation directions are generally measured clockwise from North. Angles in the usual x-y coordinate plane are measured counterclockwise from +x (effectively, East). You can consider the geometry of the navigation coordinate system to be a reflection across the line y=x of the geometry of the usual x-y coordinate system.
Reflection does not change lengths or angles within a given geometry. Hence, we can use all the usual tools of vector calculation using navigation coordinates, without bothering to translate them back and forth to x-y coordinates.
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Problems like this generally can be worked using the Law of Cosines and the Law of Sines, too. It generally helps to draw a diagram so you can find the values of the angles betwee the various vectors more easily.
Markup is the amount added to the cost price of goods to cover overhead and profit.
Sue’s Corner Market has a markup of 60% on bottled water.
Let us say original price was $x.
Now price after markup is $2.
So we can make an equation like:
original price + markup price = price after markup
x + 60% of x =2
dividing both sides by 1.6
x= 1.25
So original price was 1.25 dollars.
Answer: First option.
Step-by-step explanation:
The complete exercise is attached.
In order to solve this exercise, it is necessary to remember the following property:
The Multiplication property of Equality states that:
In this case, the equation that Jada had is the folllowing:
Jada needed to solve for the variable "x" in order to find its value.
The correct procedure to solve for for "x" is to multiply both sides of the equation by 108. Then, you get:
As you can notice in the picture, Jada did not multiply both sides of the equation by 108, but multiplied the left side by <em> </em>and the right side by
.
Therefore,you can conclude that Jada should have multiplied both sides of the equation by 108.
