Divide the 240g into the ratio 5:3:4?

In a recently administered iq test, the scores were distributed normally, with mean 100 and standard deviation 15. what proporti

iragen [17]

To solve for proportion we make use of the z statistic. The procedure is to solve for the value of the z score and then locate for the proportion using the standard distribution tables. The formula for z score is:

z = (X – μ) / σ

where X is the sample value, μ is the mean value and σ is the standard deviation

when X = 70

z1 = (70 – 100) / 15 = -2

Using the standard distribution tables, proportion is P1 = 0.0228

when X = 130

z2 = (130 – 100) /15 = 2

Using the standard distribution tables, proportion is P2 = 0.9772

Therefore the proportion between X of 70 and 130 is:

P (70<X<130) = P2 – P1

P (70<X<130) = 0.9772 - 0.0228

P (70<X<130) = 0.9544

Therefore 0.9544 or 95.44% of the test takers scored between 70 and 130.

6 0

3 years ago

An adult blinks about 450 times in 30 minutes. A 12-year-old blinks 150 times in 15 minutes.How many more times does an Adult bl

Scilla [17]

Answer:

1.5 times

Step-by-step explanation:

450=30 minutes

450*2=900=60 minutes

150=15 minutes

150*4=600=60 minutes

900/600=1.5 times

5 0

3 years ago

Read 2 more answers

Shane set his watch 18 seconds behind, and it falls behind another 2 seconds every day. How many days has it been since Shane la

suter [353]

Answer:

14 days

Step-by-step explanation:

18 seconds on day 1

44-18=26

26/2=13 days

Day 1 +13 Additional days=14 days

7 0

2 years ago

(Plz help! I'll mark brainliest) <br> Q) Which statements are true about the graphed function?

SSSSS [86.1K]

Answer:

the amplitude of the function is 2.5

4 0

2 years ago

One mirror is to be in the shape of a triangle whose height is 6 feet less than twice the base of the mirror. If the mirror has

Vlad1618 [11]

Answer:

Base of the mirror is 12 feet and height of the mirror is 18 feet.

Step-by-step explanation:

Given:

Area of the triangular mirror = 108 sq ft.

Let base (b) of the mirror be x.

Now given:

height is 6 feet less than twice the base of the mirror

So we can say that;

Height (h) = $2x-6$

We need to find the base and height of the mirror.

Solution:

Now we know that mirror is in triangular shape so we will apply area of triangle formula to find base and height.

Now Area of triangle is half times base times height.

framing in equation form we get;

$108=\frac{1}{2} \times x \times(2x-6)\\\\108=\frac{1}{2}\times x \times 2(x-3)\\\\108=x(x-3)\\\\108=x^2-3x\\\\x^2-3x-108=0$

Now we will find the roots of x by factorizing the equation we get;

$x^2-12x+9x-108=0\\\\x(x-12)+9(x-12)=0\\\\(x-12)(x+9)=0$

Now we will solve for 2 values of x we get;

$x-12=0\\\\x=12\ ft\\\\Also;\\\\x+9=0\\\\x=-9\ ft$

Now we get 2 values of 'x' one positive and one negative.

Since x is base of the triangle which cannot be negative.

so we will discard the negative value.

Hence;

base of triangle = 12 ft

Height of the triangle = $2x-6=2\times12-6 =24-6 =18\ ft$

Hence Base of the mirror is 12 feet and height of the mirror is 18 feet.

7 0

3 years ago

Divide the 240g into the ratio 5:3:4?​

Divide the 240g into the ratio 5:3:4?