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
jolli1 [7]
3 years ago
6

How do I solve this?: The times of all 15 year olds who run a certain race are approximately normally distributed with a given m

ean = 18 sec and standard deviation = 1.2 sec. What percentage of the runners have times less than 14.4 sec?

Mathematics
2 answers:
ruslelena [56]3 years ago
6 0

Answer:

0.15%

Step-by-step explanation: i took the test

Effectus [21]3 years ago
5 0
We need to 'standardise' the value of X = 14.4 by first calculating the z-score then look up on the z-table for the p-value (which is the probability)

The formula for z-score:
z = (X-μ) ÷ σ

Where
X = 14.4
μ = the average mean = 18
σ = the standard deviation = 1.2

Substitute these value into the formula

z-score = (14.4 - 18) ÷ 1..2 = -3

We are looking to find P(Z < -3)
The table attached conveniently gives us the value of P(Z < -3)  but if you only have the table that read p-value to the left of positive z, then the trick is to do:
1 - P(Z<3)

From the table
P(Z < -3) = 0.0013

The probability of the runners have times less than 14.4 secs is 0.0013 = 0.13%


You might be interested in
What is 4.3(v+2.5)=8.11+4v
True [87]

Answer:

-8.8

Step-by-step explanation:

We begin by simplifying the parenthesis through multiplication. Parenthesis is a structure which signals multiplication happening.

4.3(v+2.5)=8.11+4v\\4.3v+10.75=8.11+4v

We now begin combining like terms across the equal sign by performing the inverse or doing the opposite. Move first the 8.11 by subtracting it from both sides.

4.3v+10.75-8.11=8.11-8.11+4v\\4.3v+2.64=4v

Now, move 4.3v across by subtracting it from both sides.

4.3v-4.3v+2.64=4v-4.3v

2.64=-0.3v

Finally, we divide both sides by the coefficient of v.

\frac{2.64}{-0.3} =\frac{-0.3v}{-0.3} \\-8.8=v

6 0
3 years ago
Using the quadratic formula to solve 5x = 6x- - 3, what are the values of x?
goldfiish [28.3K]

Answer:

x= -3

Step-by-step explanation:

Solve the rational equation by combining expressions and isolating the variable  x.

8 0
2 years ago
Read 2 more answers
Jerome used 3 and 1/4 gallons of gasoline while driving from school to to his baseball game. If he originally had 7 gallons in h
kozerog [31]
7 - 3 1/4 = (turn mixed number to improper fraction
7 - 13/4 = (common denominator is 4)
28/4 - 13/4 =
15/4 or 3 3/4 gallons remain in the tank

6 0
3 years ago
Read 2 more answers
Fractions and mixed numbers I need help!!!
zimovet [89]

Answer:

The answer would be D, or 3^{3} *3^{2}* 5

Step-by-step explanation:

A is 540

B is 30

C is 720

D is 360

7 0
3 years ago
Does anyobe else feelllll mad right now​
Leno4ka [110]

Answer:

meeee

Step-by-step explanation:

3 0
3 years ago
Read 2 more answers
Other questions:
  • A sail is in the form of a right triangle that is three times as high as it is wide. The snail is made from 6 square meters of m
    5·1 answer
  • Solve the inequality. 1/3a+2&lt;-2
    14·1 answer
  • Hydrologists collected water samples from a river for several years. They found 62 out of 648 samples exceeded the desired pH le
    12·1 answer
  • The total cost for Sophia to build b birdhouses is represented by the function f(b)=3.5b+24.
    7·2 answers
  • Which angle is adjacent to ADB?​
    13·1 answer
  • Minim<br> w<br> Original price: $40; Markup: 15%<br> The retail price is $
    15·1 answer
  • Someone help me with this problem its MCQ!!!!!
    14·2 answers
  • Find the measures of the angle QUESTION A.
    11·1 answer
  • Help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
    5·2 answers
  • Tamara wants to find the distance from (2, –10) to other points. For which points in the same quadrant as (2, –10) could Tamara
    10·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!