Answer: One sample z test for means
Step-by-step explanation:
From the information given, the sample size is large. It is greater than 30. Again, the population standard deviation is given. This means that the test statistic would be the z score which is determined by the formula
z = (x - µ)/σ
Where
x = sample mean
µ = population mean
σ = population standard deviation
The probability value would be determined from the normal distribution table.
Therefore, the hypothesis test that should be used is
One sample z test for means
The expression that describes all of the values for which the graph is positive and decreasing is all real values of x where x < -1
<h3>Which describes all of the values for which the graph is positive and decreasing?</h3>
The equation of the function is given as:
f(x) = (x - 3)(x + 1)
When the value of the graph is positive, we have:
f(x) > 0
So, the function becomes
(x - 3)(x + 1) > 0
Split the above inequality
x - 3 > 0 and x + 1 > 0
Solve for x in the inequalities
x > 3 and x > -1
Hence, the expression that describes all of the values for which the graph is positive and decreasing is all real values of x where x < -1
Read more about intervals at:
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Answer:
The table of values and their graph show above a straight line that passes through the origin. This indicates that the relationship between the two currencies is in direct proportion. Think about what this means in real terms – if you have ten times more dollars than another person, when you both exchange your money, you will still have ten times more money. Notice also that the graph passes through the origin; this makes sense as if you have no dollars you will get no pounds!
We can express these relationships algebraically as well as graphically.
Answer: 14 red, 7 green, 44 blue
Step-by-step explanation:
First, use the letter <em>r</em> as a variable to represent the number of red Legos. The number of green Legos (<em>g</em>) is 7 less than the number of red Legos, or <em>g = r-7.</em> The number of blue Legos (b) is 2 more than 3 times the number of red Legos, or <em>b = 3r+2</em>. The total number of Legos is the number of red + green + blue Legos, which can be represented as <em>65 = r+g+b</em>.
Substitute the equations for g and b in. This should give you a final equation of <em>65 = r+(r-7)+(3r+2)</em>. To solve for the number of <u>red</u> Legos, first add up all of the terms to get <em>65 = 5r-5</em>. Now add 5 to each side (70<em> = 5r</em>). Finally, divide each side by 5 (r = 14).
To find the number of <u>green</u> Legos, substitute the number of red Legos (14) into the equation for the green Legos (<em>g = r-7</em>). This should get you the equation <em>g = 14-7</em> which simplifies to g = 7.
To find the number of <u>blue</u> Legos, substitute the number of red Legos (14) into the equation for the blue Legos (<em>b = 3r+2</em>). This gives you the equation <em>b = (3*14)+2.</em> First, multiply 3 and 14 to get <em>b = 42+2</em>. Finally, add them together to get b = 44.
