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4 years ago

How do you work out the mean mark ?

Mathematics

1 answer:

sattari [20]4 years ago

4 0

Answer:

The mean is the average of the numbers. It is easy to calculate: add up all the numbers, then divide by how many numbers there are. In other words it is the sum divided by the count.

Step-by-step explanation:

plz give brainliest

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Totally forgot how to do these?

PtichkaEL [24]

I’m just “answering” this because brainless told me to help out 4 ppl so

5 0

3 years ago

If 20,x,y,z,25 are in AP .find the value of X,y,z.

Kamila [148]

Answers:

x = 21.25
y = 22.5
z = 23.75

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Work Shown:

AP = arithmetic progression, which is the same as arithmetic sequence

d = common difference

x = 20+d
y = 20+2d
z = 20+3d

Notice how we scale up the d terms d, 2d, 3d, counting up by 1 each time.

So that must mean 25 is the same as 20+4d

20+4d = 25

4d = 25-20

4d = 5

d = 5/4

d = 1.25

and therefore,

x = 20+d = 20+1.25 = 21.25
y = 20+2d = 20+2*1.25 = 22.5
z = 20+3d = 20+3*1.25 = 23.75

We could convert these to fraction form, but I find decimal form is easier in this case.

5 0

3 years ago

You are facing North. Turn 90 degrees left. Turn 180 degrees right. Reverse the direction. Turn 90

Reil [10]

Answer:

i believe that it's north

6 0

3 years ago

How do I solve for y is 230=55-y

insens350 [35]

Answer:

-175

Step-by-step explanation:

230 = 55-y

230 - 55=-y

175= - y

y= -175

Just move the numbers to one side and variables to the other

8 0

4 years ago

Read 2 more answers

Suppose 462 of 500 randomly selected college students said they would be embarrassed to truthfully admit they could not read at

ANEK [815]

Answer:

We conclude that there is a significant difference in the proportion of all college students who would be embarrassed by these two admissions.

Step-by-step explanation:

We are given that 462 of 500 randomly selected college students said they would be embarrassed to truthfully admit they could not read at a fourth grade level.

Further suppose 135 of 500 randomly selected college students said they would be embarrassed to truthfully admit they could not "do math" at a fourth grade level (like fractions).

Let $p_1$ = proportion of college students who would be embarrassed to truthfully admit they could not read at a fourth grade level.

$p_2$ = proportion of college students who would be embarrassed to truthfully admit they could not "do math" at a fourth grade level.

So, Null Hypothesis, $H_0$ : $p_1-p_2$ = 0 or $p_1= p_2$ {means that there is not any significant difference in the proportion of all college students who would be embarrassed by these two admissions}

Alternate Hypothesis, $H_A$ : $p_1-p_2$ $\neq$ 0 or $p_1\neq p_2$ {means that there is a significant difference in the proportion of all college students who would be embarrassed by these two admissions}

The test statistics that would be used here Two-sample z proportion statistics;

T.S. = $\frac{(\hat p_1-\hat p_2)-(p_1-p_2)}{\sqrt{\frac{\hat p_1(1-\hat p_1)}{n_1}+\frac{\hat p_2(1-\hat p_2)}{n_2} } }$ ~ N(0,1)

where, $\hat p_1$ = sample proportion of college students who would be embarrassed to admit they could not read at a fourth grade level = $\frac{462}{500}$ = 0.924

$\hat p_2$ = sample proportion of college students who would be embarrassed to admit they could not "do math" at a fourth grade level = $\frac{135}{500}$ = 0.27

$n_1$ = sample of college students = 500

$n_2$ = sample of college students = 500

So, test statistics = $\frac{(0.924-0.27)-(0)}{\sqrt{\frac{0.924(1-0.924)}{500}+\frac{0.27(1-0.27)}{500} } }$

= 28.28

The value of z test statistics is 28.28.

Also, P-value of the test statistics is given by;

P-value = P(Z > 28.28) = Less than 0.0005%

Now, at 0.10 significance level the z table gives critical values of -1.645 and 1.645 for two-tailed test.

Since our test statistics doesn't lie within the range of critical values of z, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.

Therefore, we conclude that there is a significant difference in the proportion of all college students who would be embarrassed by these two admissions.

5 0

4 years ago