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]
3 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]3 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
Arrange the steps in correct order to show that the sum, over the set of people at a party, of the number of people a person has
anyanavicka [17]

Answer:

86

Step-by-step explanation:

4 0
3 years ago
Simplify: 3 5 power x 3-2power
natta225 [31]

Answer:

3 to the power of 5 is 243 and 3 to the power of 2 is 9 and

243 x 9 is 2187

Step-by-step explanation:

7 0
3 years ago
Find the volume of given solid.plz give explaination.​
lara31 [8.8K]

Answer:

480 cm^3

Step-by-step explanation:

Total volume is the sum of the volumes of the 3 cuboids.

Cuboid at the bottom:

V = l×b×h

V = 12 × 5 × 4 = 240

Both on top are identical.

Their height is 10-4= 6 cm

Each has volume = 5×4×6 = 120

Total Volume = 240 + 120 + 120

= 480 cm^3

7 0
3 years ago
I need help 3x²+7x+3=0
Phoenix [80]
Solve the equation for
x
x
by finding
a
a
,
b
b
, and
c
c
of the quadratic then applying the quadratic formula.
Exact Form:
x
=
−
7
±
√
13
6
x
=
-
7
±
13
6
Decimal Form:
x
=
−
0.56574145
…
,
−
1.76759187
5 0
3 years ago
find the length of the hypotenuse of a right triangle with legs of 12 ft and 16 ft. A 11 ft. B 18 ft. C 20 ft. D 28 ft
9966 [12]
C 20ft, shoukd be the answer.
3 0
3 years ago
Other questions:
  • Main Street Hardware sells paint thinner in gallons and fractions of gallons according to customer needs. On Saturday, the store
    5·1 answer
  • How does tan^-1(17/2)=83.3?
    7·1 answer
  • M.s. alonso ordered 4,000 markers for her store. Only 1/10 of them arrived. How many markers did she receive?
    7·2 answers
  • When is it easiest to determine the percent of a number using a fraction? Using a decimal?
    13·1 answer
  • Graph y=3sinx and y=sin 3x on the same axes. label the graph of each function.
    13·1 answer
  • Can someone help me solve 14 step by step like how to figure out the answer, the answer is A I just don't know how to do it?
    12·1 answer
  • Evaluate the expression using the order of operation (13.1 times 3) + 5.21
    9·1 answer
  • Determine the common factor and HCF for each of the following terms.
    8·1 answer
  • What is the difference when adding whole numbers and adding decimals?
    6·1 answer
  • Add (x^3 -2x^2+4) + (2x^3+x^2-2) express in standard form​
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!