Answer:
The correct option is 1.148 < σ < 6.015
Explanation:
The 99% confidence interval for the standard deviation is given below:

Where:


Therefore, the 99% confidence interval is:


Therefore, the option 1.148 < σ < 6.015 is correct
Answer:
3 groups of 5 sopranos and 12 altos
Step-by-step explanation:
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.
So, The Crayola Crayon company can make 2400 crayons in 4 minutes. In other words, every 4 minutes they can make 2400 crayons, right? So, in 15 minutes how many would they have made? Well, what we do is we divide 15 by 4 which is 3.75. Then we multiply the result, 3.75, by 2400. 3.75 * 9000. So, in 15 minutes, Crayola would have made 900 crayons!
4/2400 = 15/x
Step 1: Cross Multiply
4/2400 = 15/x
4 * x = (15) * (2400)
4x = 36000
Step 2: Divide both sides by 2
4x/4 = 36000/2
x = 9000
The answer is, 9000!!! :D
Answer:
A, B, and D all only have one solution.
Step-by-step explanation: