All categories

3 years ago

Pls help !!!!! i'll mark brainliest

Mathematics

1 answer:

ExtremeBDS [4]3 years ago

5 0

Answer:

Last year there were 550 bison in the heard and this year it is 10% larger.

10% is also 10/100 or 0.10

To find 10% of the heard last year

550 x.0.10 = 55. To find the number in the heard this year add 550 (last year) + 55 (10% growth) = 605 or,

to find how many there are now last years heard size was 100% of the heard or 1.00. To find any percent more add it to 1.00 and multiply by the starting amount.

550 x 1.10 = 605

For the second example.

If there are 550 bison in the heard this year, and this year was a decrease of 10% from last year we can express last year's number like this.

550 = (x - (x * 0.10)) simplify;

550 = 1x - 0.10x

550 = 0.90x

Divide both sides by 0.90

x = 611.11 but it's hard to have 0.11 of a bison so realistically 611 bison last year. Subtract 10% or 61 and you indeed have 550 this year.

You might be interested in

25 Points!!! Please help me!!! Will give Brainliest!!!

olga2289 [7]

Answer:

SAS

Step-by-step explanation:

We can use the SAS postulate because we are given 2 sides with the included angle. If two sides with the included angle of one triangle are congruent to two sides and the included angle of another triangle, the two triangles are congruent.

5 0

3 years ago

Scores of an IQ test have a bell-shaped distribution with a mean of 100 and a standard deviation of 17. Use the empirical rule

Citrus2011 [14]

Answer:

(a) 95% of people has an IQ score between 66 and 134.

(b) 5% of people has an IQ score less than 66 or greater than 134.

(c) 2.5% of people has an IQ score greater than 134.

Step-by-step explanation:

We are given that Scores of an IQ test have a bell-shaped distribution with a mean of 100 and a standard deviation of 17.

Let X = <u><em>Scores of an IQ test </em></u>

So, X ~ Normal( $\mu=100, \sigma^{2} = 17^{2}$ )

Now, the Empirical rule states that;

68% of the data values lies within one standard deviation of the means.
95% of the data values lies within two standard deviation of the means.
99.7% of the data values lies within three standard deviation of the means.

That is; [ $\mu-\sigma,\mu+\sigma$ ] = [ $100-17,100+17$ ]

= $[83,117]$

[ $\mu-2\sigma,\mu+2\sigma$ ] = [ $100-34,100+34$ ]

= $[66,134]$

[ $\mu-3\sigma,\mu+3\sigma$ ] = [ $100-51,100+51$ ]

= $[49,151]$

(a) Percentage of people that has an IQ score between 66 and 134 is given by = P(66 < X < 134)

As seen above this value lies in the second category which means that 95% of people that has an IQ score between 66 and 134.

(b) Percentage of people that has an IQ score less than 66 or greater than 134 is given by;

As we know that 95% of the data values lies within 66 and 134, so the percentage of people that has an IQ score less than 66 or greater than 134 is = 100% - 95% = 5%.

(c) Since it has been calculated above that 5% of people has an IQ score less than 66 or greater than 134 which means half of these people will lie below score of 66 and half of these will lie above score of 134.

SO, percentage of people that has an IQ score greater than 134 = $\frac{5\%}{2}$ = 2.5%