a compass and a ruler cost $4. the compass is .90 cent more than the ruler. how much does the compass cost

2. A hang glider dropped his cell phone from a height of 450 feet. How many seconds did it take the cell phone to reach the grou

Neko [114]

Answer:

2. A hang glider dropped his cell phone from a height of 450 feet. How many seconds did it take the cell phone to reach the ground?225feet

7 0

3 years ago

Scores of an IQ test have a bell-shaped distribution with a mean of 100 and a standard deviation of 13. Use the empirical rule

Yuri [45]

Answer:

(a) 68% of people has an IQ score between 87 and 113.

(b) 5% of people has an IQ score less than 74 or greater than 126.

(c) 0.15% of people has an IQ score greater than 139.

Step-by-step explanation:

Given information:Scores of an IQ test have a bell-shaped distribution,

mean = 100

standard deviation = 13

According to the empirical rule

68% data lies between $\overline{x}-\sigma$ and $\overline{x}+\sigma$ .

95% data lies between $\overline{x}-2\sigma$ and $\overline{x}+2\sigma$ .

99.7% data lies between $\overline{x}-3\sigma$ and $\overline{x}+3\sigma$ .

(a)

$\overline{x}-\sigma=100-13=87$

$\overline{x}+\sigma=100+13=113$

$[\overline{x}-\sigma,\overline{x}+\sigma]=[87,113]$

Using empirical rule we can say that 68% of people has an IQ score between 87 and 113.

(b)

$\overline{x}-2\sigma=100-2(13)=74$

$\overline{x}+2\sigma=100+2(13)=126$

$[\overline{x}-2\sigma,\overline{x}+2\sigma]=[74,126]$

Using empirical rule we can say that 95% of people has an IQ score between 74 and 126.

The percentage of people has an IQ score less than 74 or greater than 126 is

P = 1- percent of people has an IQ score between 74 and 126.

P = 1- 95%

P = 5%

Therefore 5% of people has an IQ score less than 74 or greater than 126.

(c)

$\overline{x}-3\sigma=100-3(13)=61$

$\overline{x}+3\sigma=100+3(13)=139$

$[\overline{x}-3\sigma,\overline{x}+3\sigma]=[61,139]$

Using empirical rule we can say that 99.7% of people has an IQ score between 61 and 139.

The percentage of people has an IQ score less than 61 or greater than 139 is

P = 1- percent of people has an IQ score between 61 and 139.

P = 1- 99.7%

P = 0.3%

The percentage of people has an IQ score greater than 139 is

$P=\frac{1}{2}(0.3\%)=0.15\%$

Therefore 0.15% of people has an IQ score greater than 139.

5 0

4 years ago

Help me on number problem 1 please

Aneli [31]

The answer to this is going to be 9 and 16.

6 0

4 years ago

Read 2 more answers

Of the 10 people attending a seminar, 5 have gray hair.

Sliva [168]

Answer:

1/2

Step-by-step explanation:

So we know that there is a total of 10 people.

5 of these have grey hair.

To find the chances of a somone having grey hair, we need to divide people with grey hair over total people:

$\frac{value}{total} =probability$

This is the same division we use to find things such as percentage and ratio as well.

Now lets plug in our numbers and solve:

$\frac{5}{10}=\frac{1}{2}$

So half of the people have grey hair.

Or(in percentage):

The probability is 50% that someone will have grey hair.

Hope this hepls!

8 0

3 years ago

Read 2 more answers

5. What is the midpoint of the segment joining (12,2) and (-5,-7)? A.(5,-3) B.(9,17) C.(8.5,4.5) D.(3.5,-2.5)

photoshop1234 [79]

Number5 is (9,17)
number 6 is 5
number 7is17

3 0

3 years ago