Answer:
D
Step-by-step explanation:
Subtract 60 from 80 to get 20, and divide 20 by 80 to get 1/4, which can be converted to 25%.
Answer:
Step-by-step explanation:
y![f(x)^{-1} = inverse\\f(x)=y \\y = 1/(x^{3} \\Inverse: y=x ------------> x = 1/y^{3}\\y^{3} - \frac{1}{x} = 0\\y^{3} = \frac{1}{x}\\y = \sqrt[3]{\frac{1}{x}} \\y = \frac{\sqrt[3]{1} }{\sqrt[3]{x}} \\y = \frac{1}{\sqrt[3]{x}}](https://tex.z-dn.net/?f=f%28x%29%5E%7B-1%7D%20%20%3D%20inverse%5C%5Cf%28x%29%3Dy%20%5C%5Cy%20%3D%201%2F%28x%5E%7B3%7D%20%5C%5CInverse%3A%20y%3Dx%20------------%3E%20x%20%3D%201%2Fy%5E%7B3%7D%5C%5Cy%5E%7B3%7D%20-%20%5Cfrac%7B1%7D%7Bx%7D%20%3D%200%5C%5Cy%5E%7B3%7D%20%3D%20%5Cfrac%7B1%7D%7Bx%7D%5C%5Cy%20%3D%20%5Csqrt%5B3%5D%7B%5Cfrac%7B1%7D%7Bx%7D%7D%20%5C%5Cy%20%3D%20%5Cfrac%7B%5Csqrt%5B3%5D%7B1%7D%20%7D%7B%5Csqrt%5B3%5D%7Bx%7D%7D%20%5C%5Cy%20%3D%20%5Cfrac%7B1%7D%7B%5Csqrt%5B3%5D%7Bx%7D%7D)
Answer:
See below
Step-by-step explanation:
The score increase was 35 points. They claimed an increase of at least 50 points. For a significance level of 5%, the z-score for the situation needs to be at smaller than -1.645. For a significance level of 1%, the z-score needs to be smaller than -2.325
The z score for our situation: z = (385 - 350)/50 = 0.7
The average score of 385 of Tutor O-Rama scores is not significantly different from the average of the other students SAT scores. The evidence doesn't support their claim of being effective tutoring.
