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
Setler [38]
3 years ago
10

Scores on a test in a very large class are bell-shaped and symmetric. The mean on the test was 75, and the standard deviation wa

s 5. What percent of the scores were above 75?
Mathematics
1 answer:
Kay [80]3 years ago
7 0

Answer:

50% of the scores were above 75

Step-by-step explanation:

Problems of normally distributed(bell-shaped) samples are solved using the z-score formula.

In a set with mean \mu and standard deviation \sigma, the zscore of a measure X is given by:

Z = \frac{X - \mu}{\sigma}

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

\mu = 75, \sigma = 5

What percent of the scores were above 75?

This is 1 subtracted by the pvalue of Z when X = 75. So

Z = \frac{X - \mu}{\sigma}

Z = \frac{75 - 75}{5}

Z = 0

Z = 0 has a pvalue of 0.5

1 - 0.5 = 0.5

50% of the scores were above 75

You might be interested in
Suppose that a certain movie earns $3,000,000 in ticket sales. If 60% goes to the movie and 40% goes to theatres: Movie studios
miskamm [114]

Answer: See explanation

Step-by-step explanation:

Amount earned by movie = $3,000,000.

Percentage that went to movie = 60%

Percentage that went to theater = 40%

Revenue gotten by movie studio = 60% × $3,000,000

= 0.6 × $3,000,000

= $1,800,000

Revenue gotten by theaters = 40% × $3,000,000

= 0.4 × $3,000,000

= $1,200,000

5 0
3 years ago
What is measurement<br>​
Shkiper50 [21]
Measurement is the numerical quantitation of the attributes of an object or event, which can be used to compare with other objects or events. The scope and application of measurement are dependent on the context and discipline
4 0
3 years ago
Read 2 more answers
How are algebraic expressions used to represent and solve problem
spin [16.1K]

The purpose of solving an algebraic expression in an equation is to find the unknown variable. When two expressions are equated, they form an equation and therefore, it becomes easier to solve for the unknown terms. To solve an equation, place the variables on one side and the constants on the other side.

Sure hope this helps

8 0
2 years ago
Zool X
Mars2501 [29]
BOOKMARK is the answer to this question
4 0
3 years ago
I need help with premetier and area for 7 8 9
SCORPION-xisa [38]

The answers to the three shapes are:

Figure 7; perimeter = 16.2mm, area = 12.64 square mm

Figure 8; perimeter = 15.2inches, area = 9.61 square inches

Figure 9; perimeter = 21.47yards,  area = 16.81 square yards

<h3>What is the perimeter of a shape?</h3>

Perimeter is the outside boundary of a plane shape.

Analysis:

for figure 7, perimeter = s + s + s = 3s = 3(5.4) = 16.2mm

                   Height of triangle = \sqrt{((5.4)^{2} - (2.7)^{2}  } = 4.68

            Area of triangle = 1/2 base x height = 1/2 x 5.4 x 4.68 = 12.64mm^{2}

For figure 8, perimeter = b + b + a = 5.9 + 5.9 + 3.4 = 15.2 inches

                     Height of triangle = \sqrt{(5.9)^{2}  - (1.7)^{2} } = 5.65inches

           Area of triangle = 1/2 base x height = 1/2 x 3.4 x 5.65 = 9.61inches^{2}

For figure 9, perimeter = b + a + c = 8.2 + 4.1 + 9.17 = 21.47yards

           Area of triangle = 1/2 x base x height = 1/2 x 8.2 x 4.1 = 16.81yards^{2}

In conclusion, the perimeter and area of the given shapes are:

Figure 7; perimeter = 16.2mm, area = 12.64 square mm

Figure 8; perimeter = 15.2inches, area = 9.61 square inches

Figure 9; perimeter = 21.47yards,  area = 16.81 square yards

Learn more about perimeter of plane shapes: brainly.com/question/2569205

#SPJ1

5 0
2 years ago
Other questions:
  • Alyssa kept track of her earnings and expenses for the past week. Determine the amount of money, if any, she has at the end of t
    5·1 answer
  • Write a sentence that explains the relationship between the two numbers.
    14·1 answer
  • An easy way to simplify fractions
    15·1 answer
  • There are 16 ounces in 1 pound Chanda picked 9 pounds of cherries from her tree this year find the number of ounces of cherries
    15·1 answer
  • What's the x-intercept of y =4x + 8
    9·1 answer
  • Find the value of x. ROUND TO THE NEAREST TENTH
    12·1 answer
  • 1. Mr.Rodriguez Works at a used car dealership and earns a base pay of $1,000 per
    11·1 answer
  • Define product. give an example of two whole number factors with a product of 9
    8·1 answer
  • Help pls!! <br> You can check more than one box but number them so Ik please and ty !
    5·2 answers
  • Solve the inequality: x - 20 &lt; 35
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!