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
Gennadij [26K]
3 years ago
15

A government agency has specialists who analyze the frequencies of letters of the alphabet in an attempt to decipher intercepted

messages. In standard English​ text, a particular letter is used at a rate of 5.7​%. a. Find the mean and standard deviation for the number of times this letter will be found on a typical page of 1600 characters. muequals 91.2 ​(Do not​ round.) sigmaequals 9.3 ​(Round to one decimal place as​ needed.) b. In an intercepted​ message, a page of 1600 characters is found to have the letter occurring 102 times. Is this​ unusual?\
Mathematics
1 answer:
Andru [333]3 years ago
4 0

Answer:

A) μ = 91.2; σ = 9.3

B) No

Step-by-step explanation:

To find the mean, μ, we use the formula

μ = np, where n is the sample size and p is the probability of success (percentage of times the letter is used).

This gives us

μ = 0.057(1600) = 91.2

To find the standard deviation, we use the formula

σ = √(np(1-p)

This gives us

σ = √(1600×0.057×(1-0.057))

= √(1600×0.057×0.943) = √86.0016 = 9.2737 ≈ 9.3≈

Any value that is more than two standard deviations from the mean is considered unusual.  The value 102 is

(102-91.2)/9.3 = 10.8/9.3 = 1.16 standard deviations from the mean.  This is not statistically unusual.

You might be interested in
What is the vertical asymptote of f(x)=3/x+5
Rudiy27

Answer:

X = -5

Step-by-step explanation:

5 0
3 years ago
Read 2 more answers
276x72 pls I need help I’ll give brainlist
notsponge [240]

Answer:

19872 is your answer

Step-by-step explanation:

8 0
2 years ago
Read 2 more answers
Juan’s classroom is shaped like a rectangle.the room is 40 feet long and 25 feet’s wide which rectangle could be scale drawing o
Svetach [21]

I think there's an image needed to answer this question?

I tried answering without, but you do need the image.

If the length is 40 and the width is 25, the ration of length:width is 40:25.

This can be simplified to 8:5

So the answer would be any drawing with the following dimensions:

1. length 8 ft and width 5 ft

2. length 16 ft and width 10 ft

3. length 24 ft and width 15 ft

4. length 32 ft and width 20 ft

5. length 40 ft and width 25 ft

It's most likely not the last 3 because the sizes are very big, but yeah a scale drawing maintains the same ratio so I assume one of the options for your answers is gonna be one of the answers from 1 - 4 above (5 is the given dimensions so I highly doubt that's the answer)

8 0
3 years ago
Assume the time required to complete a product is normally distributed with a mean 3.2 hours and standard deviation .4 hours. Ho
Alex787 [66]

Answer: 3.712 hours or more

Step-by-step explanation:

Let X be the random variable that denotes the time required to complete a product.

X is normally distributed.

X\sim N(\mu=3.2\text{ hours},\ \sigma=0.4\text{ hours} )

Let x be the times it takes to complete a random unit in order to be in the top 10% (right tail) of the time distribution.

Then, P(\dfrac{X-\mu}{\sigma}>\dfrac{x-\mu}{\sigma})=0.10

P(z>\dfrac{x-3.2}{\sigma})=0.10\ \ \ [z=\dfrac{x-\mu}{\sigma}]

As, P(z>1.28)=0.10  [By z-table]

Then,

\dfrac{x-3.2}{0.4}=1.28\\\\\Rightarrow\ x=0.4\times1.28+3.2\\\\\Rightarrow\ x=3.712

So, it will take 3.712 hours or more to complete a random unit in order to be in the top 10% (right tail) of the time distribution.

3 0
3 years ago
Kittens weigh about 100 grams when born and gain 7 to 15 grams per day.If a kitten weighed 100 grams at birth and gained 8 grams
natka813 [3]
100 + 8d = 300; d = 25; The kitten will triple its weight in 25 days
8 0
3 years ago
Read 2 more answers
Other questions:
  • An employee has 2/9 of his salary with held for income tax. The percent of his salary that is with held is mostly nearly ?
    14·1 answer
  • Jenny Baked 231 cookies she kept 48 for herself and divided the rest equally among three fourth grade classes how many cookies d
    13·2 answers
  • Greatest common factor of 8 and 32.
    10·2 answers
  • Help pls appreciate it pls
    9·1 answer
  • Please help, does anyone know the answer to this?
    5·1 answer
  • What is the quotient of 78 divided by 4.68
    15·1 answer
  • Give the equation of the circle centered at the origin and passing through the point (0, -6).
    6·1 answer
  • Which equation represents the table of values?
    10·2 answers
  • Please help me best answer gets an brainlist !!!
    5·1 answer
  • What is the slope of line m?
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!