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STatiana [176]
3 years ago
9

9.50 One way to evaluate the effectiveness of a teaching assistant is to examine the scores achieved by his or her students on a

n examination at the end of the course. Obviously, the mean score is of interest. However, the variance also contains useful information— some teachers have a style that works very well with more-able students but is unsuccessful with less-able or poorly motivated students. A professor sets a standard examination at the end of each semester for all sections of a course. The variance of the scores on this test is typically very close to 300. A new teaching assistant has a class of 30 students whose test scores had a variance of 480. Regarding these students’ test scores as a random sample from a normal population, test, against a two-sided alternative, the null hypothesis that the population variance of their scores is 300.
Mathematics
1 answer:
EleoNora [17]3 years ago
5 0

Answer:

Step-by-step explanation:

Given that a professor sets a standard examination at the end of each semester for all sections of a course. The variance of the scores on this test is typically very close to 300.

H_0: s^2 = 300\\H_a: s^2 \neq 300

(Two tailed test for variance )

Sample variance =480

We can use chi square test for testing of hypothesis

Test statistic = \frac{(n-1)s^2}{\sigma^2} \\=62.4

p value = 0.0100

Since p <0.05 our significance level, we reject H0.

The sample variance cannot be claimed as equal to 300.

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92×43 show work ( I know its easy but I'm tired so help please)​
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Answer:

3956

Step-by-step explanation:

92 * 43

92 * 40 = 3680

92 * 3 = 276

3680 + 276 = 3956

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3 years ago
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horrorfan [7]

Answer:

sqrt 2

Step-by-step explanation:

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2 years ago
❊ Simplify :
Nataliya [291]
<h3>Need to Do :- </h3>
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\red{\frak{Given}}\Bigg\{ \sf \dfrac{x - 1}{ {x}^{2} - 3x + 2} + \dfrac{x - 2}{ {x}^{2} - 5x + 6 } + \dfrac{x - 5}{ {x}^{2} - 8x + 15 }

\rule{200}4

\sf\longrightarrow \small  \dfrac{x - 1}{ {x}^{2} - 3x + 2} + \dfrac{x - 2}{ {x}^{2} - 5x + 6 } + \dfrac{x - 5}{ {x}^{2} - 8x + 15 } \\\\\\\sf\longrightarrow \small  \dfrac{ x-1}{x^2-x -2x +2} +\dfrac{ x-2}{x^2-3x-2x+6} +\dfrac{ x -5}{x^2-5x -3x + 15 } \\\\\\\sf\longrightarrow\small \dfrac{ x -1}{ x ( x - 1) -2(x-1) } +\dfrac{ x-2}{x ( x -3) -2( x -3)} +\dfrac{ x -5}{ x(x-5) -3( x -5) }  \\\\\\\sf\longrightarrow \small \dfrac{ x -1}{ ( x-2) (x-1) } +\dfrac{ x-2}{( x -2)(x-3) } +\dfrac{ x -5}{ (x-3)(x-5)  } \\\\\\\sf\longrightarrow\small \dfrac{ 1}{ x-2} +\dfrac{ 1}{ x -3} +\dfrac{1}{ x -3}   \\\\\\\sf\longrightarrow   \small  \dfrac{1}{x-2} +\dfrac{2}{x-3}  \\\\\\\sf\longrightarrow   \small \dfrac{ x-3 +2(x-2)}{ ( x -3)(x-2) }  \\\\\\\sf\longrightarrow   \small \dfrac{ x - 3 +2x -4 }{ (x-3)(x-2) }     \\\\\\\sf\longrightarrow   \underset{\blue{\sf Required \ Answer  }}{\underbrace{\boxed{\pink{\frak{  \dfrac{ 3x -7}{ ( x -2)(x-3) } }}}}}

\rule{200}4

5 0
2 years ago
Read 2 more answers
The function h(x) = 12x8 + 49 is an even function. Which transformation of h(x) would result in a function that is neither even
Irina-Kira [14]

Answer:  translation 8 units to the right

Step-by-step explanation:

An even function is a function such that:

h(x) = h(-x)

and the function is odd if:

h(-x) = -h(x)

Now, let's talk about transformations:

A) Reflection over the x-axis:

When we have a point (x,y) and we do a reflection over the x-axis, the reflected point will be:

(x, -y).

Then for the case of a function:

y = h(x).

then the reflection will be:

g(x) = - y = -h(x).

And if h(x) is even, -h(x) is also even, so this is not the correct option.

B) Vertical stretch by a factor of 7.

This is written as:

g(x) = 7*h(x).

then:

g(x) = 7*h(x)

g(-x) = 7*h(-x) = 7*h(x) = g(x)

the transformation is even.

C) Translation of 8 units to the right.

We can write this as:

g(x) = h(x - 8).

Then:

g(-x) = h(-x -8) = h(x + 8)

Then g(-x) is not equal to g(x)

and also g(-x) ≠ -g(x)

So in this case the transformation is neither odd or even.

C)  horizontal compression by a factor of One-half.

This transformation is written as:

g(x) = h( (1/2)*x)

And, similar as the case of the vertical compression, in this case the transformation is also even.

3 0
3 years ago
PLS HELP THIS IS HARD ANYONE PLS
tensa zangetsu [6.8K]

Answer:

The answer is c

Step-by-step explanation:

5 0
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