Hour truck can carry a 3/4 ton load. Each brick weighs 4 lbs and 14 oz. How many bricks can the truck carry

The number of texts per day by students in a class is normally distributed with a

kobusy [5.1K]

Answer:

1, 2, 6

Step-by-step explanation:

The z score shows by how many standard deviations the raw score is above or below the mean. The z score is given by:

$z=\frac{x-\mu}{\sigma} \\\\where\ x=raw\ score,\mu=mean, \ \sigma=standard\ deviation$

Given that mean (μ) = 130 texts, standard deviation (σ) = 20 texts

1) For x < 90:

$z=\frac{x-\mu}{\sigma} \\\\z=\frac{90-130}{20} =-2$

From the normal distribution table, P(x < 90) = P(z < -2) = 0.0228 = 2.28%

Option 1 is correct

2) For x > 130:

$z=\frac{x-\mu}{\sigma} \\\\z=\frac{130-130}{20} =0$

From the normal distribution table, P(x > 130) = P(z > 0) = 1 - P(z < 0) = 1 - 0.5 = 50%

Option 2 is correct

3) For x > 190:

$z=\frac{x-\mu}{\sigma} \\\\z=\frac{190-130}{20} =3$

From the normal distribution table, P(x > 3) = P(z > 3) = 1 - P(z < 3) = 1 - 0.9987 = 0.0013 = 0.13%

Option 3 is incorrect

4) For x < 130:

$z=\frac{x-\mu}{\sigma} \\\\z=\frac{130-130}{20} =0$

For x > 100:

$z=\frac{x-\mu}{\sigma} \\\\z=\frac{100-130}{20} =-1.5$

From the normal table, P(100 < x < 130) = P(-1.5 < z < 0) = P(z < 0) - P(z < 1.5) = 0.5 - 0.0668 = 0.9332 = 93.32%

Option 4 is incorrect

5) For x = 130:

$z=\frac{x-\mu}{\sigma} \\\\z=\frac{130-130}{20} =0$

Option 5 is incorrect

6) For x = 130:

$z=\frac{x-\mu}{\sigma} \\\\z=\frac{160-130}{20} =1.5$

Since 1.5 is between 1 and 2, option 6 is correct

5 0

3 years ago

-324/18<br> Plz show all the steps of how you got the answer.

kodGreya [7K]

Answer:

-18

Step-by-step explanation:

Step 1 - divide the numerator and denominator by 18

-324÷18 / 18÷18

Step 2 - divide the numbers

-18 / 18÷18

-18/1

any expression divided by 1 remains the same

-18

4 0

2 years ago

If the average(arithmetic mean) of 5 and r is 7 and the average of 3 and s is 3 , what is the average of r and s?

Norma-Jean [14]

Answer:

C

Step-by-step explanation:

Calculate the values of both r and s, that is

$\frac{5+r}{2}$ = 7 ( multiply both sides by 2 )

5 + r = 14 ( subtract 5 from both sides )

r = 9

and

$\frac{3+s}{2}$ = 3 ( multiply both sides by 2 )

3 + s = 6 ( subtract 3 from both sides )

s = 3

Hence

$\frac{9+3}{2}$ = $\frac{12}{2}$ = 6 → C

5 0

3 years ago

Can someone please help me!! this assignment is due at 11:59 I need this done

Dvinal [7]

Tan(40)= x/20 => x= tan(40).20= 16,78
Ok done. Thank to me:>

8 0

2 years ago

Read 2 more answers

5(x+2/3)=3x-2/3The answer is-2.Please show work so I can understand how to solve.

kramer

5(x + 2/3) = 3x - 2/3.....distribute the 5 through the parenthesis
5x + 10/3 = 3x - 2/3 ....subtract 3x from both sides
5x - 3x + 10/3 = 3x - 3x - 2/3...combine like terms
2x + 10/3 = - 2/3 ....subtract 10/3 from both sides
2x + 10/3 - 10/3 = -2/3 - 10/3...simplify
2x = - 12/3....reduce
2x = - 4....divide both sides by 2
x = -4/2....reduces to -2

or this way...
5(x + 2/3) = 3x - 2/3.....distribute
5x + 10/3 = 3x - 2/3....multiply by lowest common denominator of 3
15x + 10 = 9x - 2 ....subtract 9x from both sides
15x - 9x + 10 = -2 ...subtract 10 from both sides
6x + 10 - 10 = -2 - 10...simplify
6x = -12.....divide both sides by 6
x = -12/6 reduces to -2

6 0

3 years ago