1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
SVEN [57.7K]
2 years ago
10

Scores on a standardized test are normally distributed with a mean of 480 and a standard deviation of 90. What proportion of the

scores are above 700? What is 25th percentile of the score? If Someone’s score is 600, what percentile is she on? What proportion of the score are between 420 and 520?
Mathematics
1 answer:
Aloiza [94]2 years ago
7 0

Answer:

Step-by-step explanation:

Since the scores on the standardized test are approximately normally distributed, we would apply the formula for normal distribution which is expressed as

z = (x - µ)/σ

Where

x = test scores.

µ = mean score

σ = standard deviation

From the information given,

µ = 480

σ = 90

1) The proportion of scores above 700 is expressed as

P(x > 700) = 1 - P(x ≤ 700)

For x = 700,

z = (700 - 480)/90 = 2.44

Looking at the normal distribution table, the probability corresponding to the z score is 0.99

P(x > 700) = 1 - 0.99 = 0.01

the proportion of scores above 700 is 0.01

2) For the 25 percentile, z = - 0.67. Therefore,

- 0.67 = (x - 480)/90

90 × - 0.67 = x - 480

- 60.3 = x - 480

x = - 60.3 + 480

x = 419.7

3) if Someone’s score is 600, then

z = (600 - 480)/90 = 1.33

From the table, the percentileis

0.91 × 100 = 91%

4) For x = 420,

z = (420 - 480)/90 = - 0.67

The proportion is 0.25

For x = 520,

z = (520 - 480)/90 = 0.44

The proportion is 0.67

The proportion of the score between 420 and 520 is

0.67 - 0.25 = 0.42

You might be interested in
There’s a picture attached xox
NARA [144]
1)  6 positive 
2) - $25 negative 
3) -8 negative 
4) 82 positive

5 0
3 years ago
Find the area of a triangle with legs that are 9mm 6mm and 12mm
Sidana [21]

Here we are given the three sides of the triangle.

So we have Heron's formula to find its area.

Heron's formula is given by :

A= \sqrt{S(S-A)(S-B)(S-C)}

where A, B and C are sides of triangle and S is semi perimeter which is given by,

S= \frac{A+B+C}{2}

plugging values of A, B and C to find S

S= \frac{9+6+12}{2}

S=13.5

Now plugging values of A, B , C and S in Heron's formula

A= \sqrt{13.5(13.5-9)(13.5-6)(13.5-12)}

A=26.14 mm²

Answer: Area of triangle is 26.14 mm².



6 0
2 years ago
(-12,14) and (6,-1)<br> write a linear equation
jarptica [38.1K]

Answer:

Step-by-step explanation:

this is were they should go

8 0
2 years ago
12−(−2) over a line 12−6÷2
joja [24]

Given 12−(−2) over a line 12−6÷2

We can use PEMDAS rule and solve the expression in the order as given below:-

1. Parentheses

2. Exponents

3. Multiplication

4. Division

5. Addition

6. Subtraction

Now solving for given expression:-

\frac{12-(-2)}{12-(\frac{6}{2})}\\\\=\frac{12+2}{12-3}\\\\=\frac{14}{9}

So final answer is 14/9 i.e. 14 over 9.

7 0
2 years ago
Using examples, describe the following.
Hunter-Best [27]

Answer:

1. An intuitive understanding of number, their magnitude, relationships, and how they are affected by operations.

2. The ability to work outside the traditionally taught algorithms.

3. The ability to perform mental mathematics

4. The ability to look at the world and make comparisons.

5. (In non-human animals) The ability to perceive changes in the number of things in a collection.

4 0
3 years ago
Other questions:
  • What is the nearest 100 of 829
    13·1 answer
  • A baker determined the annual profit in dollars from selling cupcakes using p(n)=41n-0.06n2, where n is the number of cupcakes s
    9·1 answer
  • after flying at an altitude of 50 meters, a helicopter starts to descend when its ground distance from the landing pad is 11 kil
    10·1 answer
  • PLEASE HELP! Whoever solves it first gets Brainliest!
    7·1 answer
  • consider a circle with a radius of 10 centimeters. What is the length of the arc that measures 60° for the given circle.
    7·1 answer
  • Please help me?!!!!!!!
    6·2 answers
  • This is my last question and I don’t get it
    7·2 answers
  • The PTA makes a $5.00 profit on each school sweatshirt they sell. If they made a
    15·1 answer
  • 10 x 9= what is it help
    11·2 answers
  • Help me pls im begging yall​
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!