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
GrogVix [38]
3 years ago
5

The scores on an exam are normally distributed, with a mean of 75 and a standard deviation of 5. What percent of the scores are

less than 80?
A. 50%
B. 84%
C. 13.5%
D. 16%
Mathematics
1 answer:
stellarik [79]3 years ago
5 0

Answer:

B. 84%

Step-by-step explanation:

Given

Mean= π=75

Standard Deviation= σ=5

As we have to calculate the percentage of score less than 80, we will find the z-score of 80

z=(x-μ)/σ

=  (80-75)/5

=5/5

=1

The z-score table value for 1 is 0.8413.

For converting this value into percentage, the value will be multiplied by 100.

So,

Percentage of students whose score is less than 80 = 0.8413*100

=84.13%

Rounding off gives us : 84%

So option B is the correct answer..

You might be interested in
The rule as a mapping for the translation of a rectangle is (x, y) → (x – 2, y + 7). Which describes this translation?
julia-pushkina [17]

Answer:

a translation of 2 units to the left and 7 units up (D)

Step-by-step explanation:

5 0
3 years ago
Read 2 more answers
What is the value of z in the equation 3z - 7 = 14?
baherus [9]
1st add 7 to both sides : 3z = 21, 2nd divide both sides with 3: z = 7
5 0
3 years ago
8 to the power of negative 2 × a to the power of 7
solniwko [45]
I'm sorry, all you did was say something. We need a question if you want an answer.
5 0
3 years ago
A parallelogram is a four-sided figure
stellarik [79]
The sum of the parallelogram is 22 because I did the test
4 0
2 years ago
In​ 2000, a company had 1147 stores nationwide. By​ 2002, this total had grown to 1542. If the number of stores continues to gro
mr_godi [17]

12226 stores will be there in 2016

<em><u>Solution:</u></em>

<em><u>The growth function is given as:</u></em>

y = a(1+r)^t

Where,

y is the future value

a is the initial value

r is the growth rate

t is the number of years

From given,

In​ 2000, a company had 1147 stores nationwide

By​ 2002, this total had grown to 1542

Therefore,

y = 1542

a = 1147

t = 2000 to 2002 = 2 years

r = ?

<em><u>Substituting we get,</u></em>

1542 = 1147(1+r)^2\\\\(1+r)^2 = \frac{1542}{1147}\\\\(1+r)^2 = 1.34437

Taking square root of both sides

1+ r = 1.1594\\\\r = 1.1594 - 1\\\\r = 0.1594

<em><u>If the number of stores continues to grow exponentially at the same​ rate, how many stores will there be in​ 2016?</u></em>

Therefore,

y = ?

a = 1147

r = 0.1594

t = 2000 to 2016 = 16 years

<em><u>Substituting we get,</u></em>

y = 1147(1 + 0.1594)^{16}\\\\y = 1147(1.1594)^{16}\\\\y = 1147 \times 10.6593\\\\y = 12226.3311 \approx 12226

Thus 12226 stores will be there in 2016

4 0
4 years ago
Other questions:
  • How to round 295,245 to the nearest integer?
    5·1 answer
  • Maria will spin the arrow on the spinner three times. What is the probability that the arrow will stop on A, then B, then C?
    8·1 answer
  • Sharon is working her way through school. She works two part-time jobs for a total of 22 hours a week. Job A pays $5.90 per hour
    8·1 answer
  • What is the value of sin X
    9·2 answers
  • Examples of parallel lines ​
    14·2 answers
  • The point (17,−9) is translated to the point (6,2). Select the description of the translation.
    8·1 answer
  • True or false..How do I know if it's no solution
    11·1 answer
  • HELP!! 15 POINTS
    15·1 answer
  • I neeed help plz 30 points
    9·1 answer
  • What is the slope of PV?
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!