You can use the identity
cos(x)² +sin(x)² = 1
to find sin(x) from cos(x) or vice versa.
(1/4)² +sin(x)² = 1
sin(x)² = 1 - 1/16
sin(x) = ±(√15)/4
Then the tangent can be computed as the ratio of sine to cosine.
tan(x) = sin(x)/cos(x) = (±(√15)/4)/(1/4)
tan(x) = ±√15
There are two possible answers.
In the first quadrant:
sin(x) = (√15)/4
tan(x) = √15
In the fourth quadrant:
sin(x) = -(√15)/4
tan(x) = -√15
1. 2 3/4 = 11/4(2 * 4 + 3)
2. 1 1/4 = 5/4(1 * 4 + 1)
11/4 * 5/4 = 55/16 OR 3 7/16 if simplified.
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.
Answer:
Step-by-step explanation: