Answer:
-5
Step-by-step explanation:
-4x +10 =5(x +11)
-4x +10 =5x +55
-4x - 5x =55 - 10
-9x =45
x=-45 :9
x=-5
Answer:
I actually needed help with the answer but now I think about it the answer is answer C. $50
Step-by-step explanation:
Answer:
I think that it is B. 49.99
Step-by-step explanation:
Answer: 1.88
Step-by-step explanation:
The confidence interval for population mean is given by :-
Given : Significance level :
Critical value :
By using the standard normal distribution table for z, we find the critical value of corresponds to the p-value 0.03.
Hence, the z-value that was used in the computation must be 1.88 .
Sample Mean 25 23
Sample Variance 27 7.56
Sample Size 45 36
As the statistical advisor to Ajax, would you recommend purchasing Allied's machine? Explain.
Answer:
z(s) is in the acceptance region. We accept H₀ we did not find a significantly difference in the performance of the two machines therefore we suggest not to buy a new machine
Step-by-step explanation:
We must evaluate the differences of the means of the two machines, to do so, we will assume a CI of 95%, and as the interest is to find out if the new machine has better performance ( machine has a bigger efficiency or the new machine produces more units per unit of time than the old one) the test will be a one tail-test (to the left).
New machine
Sample mean x₁ = 25
Sample variance s₁ = 27
Sample size n₁ = 45
Old machine
Sample mean x₂ = 23
Sample variance s₂ = 7,56
Sample size n₂ = 36
Test Hypothesis:
Null hypothesis H₀ x₂ - x₁ = d = 0
Alternative hypothesis Hₐ x₂ - x₁ < 0
CI = 90 % ⇒ α = 10 % α = 0,1 z(c) = - 1,28
To calculate z(s)
z(s) = ( x₂ - x₁ ) / √s₁² / n₁ + s₂² / n₂
s₁ = 27 ⇒ s₁² = 729
n₁ = 45 ⇒ s₁² / n₁ = 16,2
s₂ = 7,56 ⇒ s₂² = 57,15
n₂ = 36 ⇒ s₂² / n₂ = 1,5876
√s₁² / n₁ + s₂² / n₂ = √ 16,2 + 1.5876 = 4,2175
z(s) = (23 - 25 )/4,2175
z(s) = - 0,4742
Comparing z(s) and z(c)
|z(s)| < | z(c)|
z(s) is in the acceptance region. We accept H₀ we did not find a significantly difference in the performance of the two machines therefore we suggest not to buy a new machine
The very hight dispersion of values s₁ = 27 is evidence of frecuent values quite far from the mean
Answer:
(a) The first quartile is 382.27 and it means that at least el 25% of the scores are less than 382.27 points.
The second quartile is 462 and it means that at least el 50% of the scores are less than 462 points.
The third quartile is 541.73 and it means that at least el 75% of the scores are less than 541.73 points.
(b) The 99th percentile is 739.27 and it means that at least el 99% of the scores are less than 739.27 points.
Step-by-step explanation:
The first, second the third quartile are the values that let a probability of 0.25, 0.5 and 0.75 on the left tail respectively.
So, to find the first quartile, we need to find the z-score for which:
P(Z<z) = 0.25
using the normal table, z is equal to: -0.67
So, the value x equal to the first quartile is:
Then, the first quartile is 382.27 and it means that at least el 25% of the scores are less than 382.27 points.
At the same way, the z-score for the second quartile is 0, so:
So, the second quartile is 462 and it means that at least el 50% of the scores are less than 462 points.
Finally, the z-score for the third quartile is 0.67, so:
So, the third quartile is 541.73 and it means that at least el 75% of the scores are less than 541.73 points.
Additionally, the z-score for the 99th percentile is the z-score for which:
P(Z<z) = 0.99
z = 2.33
So, the 99th percentile is calculated as:
So, the 99th percentile is 739.27 and it means that at least el 99% of the scores are less than 739.27 points.
The value of x + y from the equation is 15
The equation is given as:
Add 125 to both sides of the equation
Express 125 as 100 + 25
Rewrite the equation as:
Group the expressions
Express the expressions in both groups as perfect squares
Possible equations from the above equation is:
and
Take the square roots of both sides
and
Solve for x and y in the above equations
and
So, we have:
Hence, the value of x + y is 15
Read more about quadratic functions at:
2x+ y= 3