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
Alex17521 [72]
3 years ago
6

A professor at a local university noted that the exam grades of her students were normally distributed with a mean of 73 and a s

tandard deviation of 11. If 69.5 percent of the students received grades of C or better, what is the minimum score of those who received C's?
Mathematics
1 answer:
jasenka [17]3 years ago
7 0

Answer:

The minimum score of those who received C's is 67.39.

Step-by-step explanation:

Problems of normally distributed 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 = 73, \sigma = 11

If 69.5 percent of the students received grades of C or better, what is the minimum score of those who received C's?

This is X when Z has a pvalue of 1-0.695 = 0.305. So it is X when Z = -0.51.

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

-0.51 = \frac{X - 73}{11}

X - 73 = -0.51*11

X = 67.39

The minimum score of those who received C's is 67.39.

You might be interested in
Find the area of the shaded region. Use 3.14 as an approximation.​
MA_775_DIABLO [31]

Answer:

shaded area = 113.64 cm²

Step-by-step explanation:

To find the shaded area, subtract the area of the circle from the area of the triangle.

Area of a triangle = 1/2 x base x height

⇒ area of triangle = 1/2 x 25 x 21.4 = 267.5 cm²

Area of a circle = \pi r^2 (where r is the radius)

From inspection, we can see that the diameter of the circle = 14 cm

Therefore, as the diameter = 2r, then r = 14 ÷ 2 = 7 cm

⇒ area of circle = 3.14 x 7² = 153.86 cm²

Shaded area = area of triangle - area of circle

⇒ shaded area = 267.5 - 153.86 = 113.64 cm²

8 0
2 years ago
Find the slope/rate of change of the line on the graph.
ohaa [14]

Answer:

y=-1

From where the line crosses the y axis, it goes up 1 and over 1 from each plane although its moving to the left from 0 every time. This means the slope is negative.

In the equation y=mx+b, b is the y intercept and m is the slope

plugin the info and you get y=-1x+0 or

y=-1x

Step-by-step explanation:

5 0
3 years ago
Number 8 please please please
ELEN [110]

remember that when total value is used a negative number is turned positive so it equals to 282 feet

8 0
3 years ago
Gavin borrowed $250 from his parents to buy a new mp3 player. Each week he pays his parents back $10. The function, m(w) = 250 –
Kryger [21]

Answer:

m=25

Step-by-step explanation:

You want to divide 250 by 10 to find the number of weeks it would take him to pay back his parents. which would be 25. It would take Gavin 25 weeks to pay his parents back. m(w)=0 just is telling you the worth of that part of the equation.

7 0
3 years ago
Can somebody answer these 2 questions
AnnZ [28]

Answer:

2. 12.08

3. 7.74

Step-by-step explanation:

a squared + b squared = c squared

2. 5 squared = 25, 11 squared = 121, 25 + 121 = 146, the squre root of 146 is 12.08

3.19 squared = 361, 421 - 361 = 60 60 squared = 7.74

3 0
3 years ago
Read 2 more answers
Other questions:
  • A bowl has 85 pieces of candy. Nineteen children empty the bowl of candy. Some children take 3 pieces, some children take 5 piec
    11·1 answer
  • Together Louisa and kill scored more than 30 points in the basketball game. If Kill scored 12 points how many points P did Louis
    9·1 answer
  • select yes or no to indicate if a rectangle with the given dimensions whould have a perimeter of 50 inches
    13·1 answer
  • Y + 1/2 = 7/10 solve for y
    14·2 answers
  • Under his cell phone plan, Owen pays a flat cost of $67.50 per month and $4 per gigabyte. He wants to keep his bill at $71.90 pe
    15·1 answer
  • What is the sum of 5.439 + 3.200
    9·1 answer
  • 17.
    11·1 answer
  • 4% of 50<br> Percent of a quantity <br> M
    6·1 answer
  • 2.
    15·2 answers
  • In a study of cell phone usage and brain hemispheric​ dominance, an Internet survey was​ e-mailed to 6965 subjects randomly sele
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!