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3 years ago

In a exam 90% students passed.if 15 students failed,find the number of students appeared in the examination?

Mathematics

1 answer:

inysia [295]3 years ago

5 0

Answer:

150

Step-by-step explanation:

10%=15

100%=150

15 x 10=150

to check find 90% of 150 which is 135

150-135=15

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If tan 0 = -5, find the cot 0

Irina-Kira [14]

Answer:

Step-by-step explanation:

cot(theta) = 1 / tan(theta)

cot(theta) = 1 / -5

cot(theta) = - 0.2

4 0

3 years ago

The city of Madison regularly checks the quality of water at swimming beaches located on area lakes. Fifteen times the concentra

Maksim231197 [3]

Answer:

The sample standard deviation is 393.99

Step-by-step explanation:

The standard deviation of a sample can be calculated using the following formula:

$s=\sqrt[ ]{\frac{1}{N-1} \sum_{i=1}^{N}(x_{i}-{\displaystyle \textstyle {\bar {x}}}) ^{2} }$

Where:

$s=$ Sample standart deviation

$N=$ Number of observations in the sample

${\displaystyle \textstyle {\bar {x}}}=$ Mean value of the sample

and $\sum_{i=1}^{N}(x_{i}-{\displaystyle \textstyle {\bar {x}}}) ^{2} }$ simbolizes the addition of the square of the difference between each observation and the mean value of the sample.

Let's start calculating the mean value:

$\bar {x}=\frac{1}{N} \sum_{i=1}^{N}x_{i}$

$\bar {x}=\frac{1}{15}*(180+1600+90+140+50+260+400+90+380+110+10+60+20+340+80)$

$\bar {x}=\frac{1}{15}*(3810)$

$\bar {x}=254$

Now, let's calculate the summation:

$\sum_{i=1}^{N}(x_{i}-\bar {x}) ^{2} }=(180-254)^2+(1600-254)^2+(90-254)^2+...+(80-254)^2$

$\sum_{i=1}^{N}(x_{i}-\bar {x}) ^{2} }=2173160$

So, now we can calculate the standart deviation:

$s=\sqrt[ ]{\frac{1}{N-1} \sum_{i=1}^{N}(x_{i}-{\displaystyle \textstyle {\bar {x}}}) ^{2} }$

$s=\sqrt[ ]{\frac{1}{15-1}*(2173160)}$

$s=\sqrt[ ]{\frac{2173160}{14}}$

$s=393.99$

The sample standard deviation is 393.99

3 0

4 years ago

Select the answer choice that is equivalent to the expression given below.

pochemuha

Answer:

B. 23x-10

Step-by-step explanation:

3 0

3 years ago

What is the slope of this line?

Anvisha [2.4K]

(-4,5),(0,6)

slope = rise/run
tip... you have to crawl (run) before you run (rise) .

you can use the slope formula
$\frac{5 - 6}{ - 4 - 0} = \frac{ - 1}{ - 4} = \frac{1}{4}$
1/4

5 0

3 years ago

Subtract 7x-9 from2x^2-11

strojnjashka [21]

Answer:

The answer is: $2x^2-7x-2$