Answer:
50.7
Step-by-step explanation:
Answer:
the subtraction
Step-by-step explanation:
Answer:
The score is 
Step-by-step explanation:
From the question we are told that
The population mean is 
The standard deviation is 
From the question we are told that the score follow a normal distribution
i.e 
The proportion of score in the top 10% is mathematically

Where x is the minimum score required to be in the top 10%
Now the 
So

So

So the critical value of 0.10 from the normal distribution table is 
So


4x - 3(x + 5) > 7 - 4(x + 6) |use distributive property; a(b + c) = ab + ac
4x - 3x - 15 > 7 - 4x - 24 |combine items
x - 15 > -4x - 17 |add 15 to both sides
x > -4x - 2 |add 4x to both sides
5x > -2 |divide both sides by 5
x > - 2/5
Answer:
The probability that the proportion of passed keypads is between 0.72 and 0.80 is 0.6677.
Step-by-step explanation:
According to the Central limit theorem, if from an unknown population large samples of sizes <em>n</em> > 30, are selected and the sample proportion for each sample is computed then the sampling distribution of sample proportion follows a Normal distribution.
The mean of this sampling distribution of sample proportion is:

The standard deviation of this sampling distribution of sample proportion is:

Let <em>p</em> = the proportion of keypads that pass inspection at a cell phone assembly plant.
The probability that a randomly selected cell phone keypad passes the inspection is, <em>p</em> = 0.77.
A random sample of <em>n</em> = 111 keypads is analyzed.
Then the sampling distribution of
is:

Compute the probability that the proportion of passed keypads is between 0.72 and 0.80 as follows:


Thus, the probability that the proportion of passed keypads is between 0.72 and 0.80 is 0.6677.