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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..

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Find the slope of the line that contains the two points (0,1) and (1,3)
klio [65]

Answer:

m=2 or y=2x+1

Step-by-step explanation:

first use the y2-y1/x2-x1 formula and then use y=mx+b formula

plug in 3 for y2 and 1 for y1

plug in 1 for x2 and 0 for x1

\frac{3-1}{1-0} =\frac{2}{1} =2

so ur slope is 2

_______________

for y=mx+b *extra info ig if u need it just incase*

i usually use the first point for this but u can use any one u want

plug in 0 for x

plug in 1 for y

and plug in 2 for m

1=2(0)+b

2*0=0

1=0+b

subtract o on both sides

1=b and b is ur y-intercept

y=2x+1

hope this helps

7 0
3 years ago
Lines m and n are parallel. Which angle has a measure of 110°?
grigory [225]
This might help you..need more information

6 0
2 years ago
What can you tell about a triangle when given three side lengths?
Genrish500 [490]
Check whether it is possible to have a triangle with the given side lengths for example 7,9,13 then add any two sides and see if it is greater than the other side. Example the sum of 7 and 9 is 16 and 16 is greater than 13
3 0
2 years ago
Consider the next 1000 90% CIs for μ that a statistical consultant will obtain for various clients. Suppose the data sets on whi
Ivenika [448]

Answer:

90% CI expects to capture u 90% of time

(a) This means 0.9 * 1000 = 900 intervals will capture u

(b) Here we treat CI as binomial random variable, having probability 0.9 for success

n = 1000

p = 0.9

For this case, applying normal approximation to binomial, we get:

mean = n*p= 900

variance = n*p*(1-p) = 90

std dev = 9.4868

We want to Find : P(890 <= X <= 910) = P( 889.5 < X < 910.5) (integer continuity correction)

We convert to standard normal form, Z ~ N(0,1) by z1 = (x1 - u )/s

so z1 = (889.5 - 900 )/9.4868 = -1.11

so z2 = (910.5 - 900 )/9.4868 = 1.11

P( 889.5 < X < 910.5) = P(z1 < Z < z2) = P( Z < 1.11) - P(Z < -1.11)

= 0.8665 - 0.1335

= 0.733

6 0
3 years ago
If f'(x) = 12x^3 - 2x^2 - 17 and f(1) = 8 , find f(x).
Cloud [144]

Answer:

f(x) =  3x⁴ - \frac{2X^{3} }{3} - 17x +  \frac{68}{3}

Step-by-step explanation:

To find f'(x), we will follow the steps below:

We will start by integrating both-side of the equation

∫f'(x) = ∫(12x^3 - 2x^2 - 17)dx

f(x)  = 3x⁴ - \frac{2X^{3} }{3} - 17x + C

Then we go ahead and find C

f(1) = 8

so we will replace x by 1 in the above equation and solve for c

f(1)  = 3(1)⁴ - \frac{2(1)^{3} }{3} - 17(1) + C

8 = 3 - \frac{2}{3} - 17 + C

C =8 - 3 + 17 + \frac{2}{3}

C = 22 +  \frac{2}{3}

C =\frac{66 + 2}{3}

C = \frac{68}{3}

f(x) =  3x⁴ - \frac{2X^{3} }{3} - 17x +  \frac{68}{3}

7 0
3 years ago
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