Round 12,351 to the nearest hundred

A population has a mean of 200 and a standard deviation of 50. Suppose a sample of size 100 is selected and x is used to estimat

zmey [24]

Answer:

a) 0.6426 = 64.26% probability that the sample mean will be within +/- 5 of the population mean.

b) 0.9544 = 95.44% probability that the sample mean will be within +/- 10 of the population mean.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

When the distribution is normal, we use the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

In this question, we have that:

$\mu = 200, \sigma = 50, n = 100, s = \frac{50}{\sqrt{100}} = 5$

a. What is the probability that the sample mean will be within +/- 5 of the population mean (to 4 decimals)?

This is the pvalue of Z when X = 200 + 5 = 205 subtracted by the pvalue of Z when X = 200 - 5 = 195.

Due to the Central Limit Theorem, Z is:

$Z = \frac{X - \mu}{s}$

X = 205

$Z = \frac{X - \mu}{s}$

$Z = \frac{205 - 200}{5}$

$Z = 1$

$Z = 1$ has a pvalue of 0.8413.

X = 195

$Z = \frac{X - \mu}{s}$

$Z = \frac{195 - 200}{5}$

$Z = -1$

$Z = -1$ has a pvalue of 0.1587.

0.8413 - 0.1587 = 0.6426

0.6426 = 64.26% probability that the sample mean will be within +/- 5 of the population mean.

b. What is the probability that the sample mean will be within +/- 10 of the population mean (to 4 decimals)?

This is the pvalue of Z when X = 210 subtracted by the pvalue of Z when X = 190.

X = 210

$Z = \frac{X - \mu}{s}$

$Z = \frac{210 - 200}{5}$

$Z = 2$

$Z = 2$ has a pvalue of 0.9772.

X = 195

$Z = \frac{X - \mu}{s}$

$Z = \frac{190 - 200}{5}$

$Z = -2$

$Z = -2$ has a pvalue of 0.0228.

0.9772 - 0.0228 = 0.9544

0.9544 = 95.44% probability that the sample mean will be within +/- 10 of the population mean.

7 0

3 years ago

A collection of coins contains a total of sixteen dimes and quarters. It is worth $2.20 in all. How many dimes are in the collec

grin007 [14]

9514 1404 393

Answer:

12 dimes

Step-by-step explanation:

Let q represent the number of quarters. Then the number of dimes is 16-q and the total value is ...

0.25q +0.10(16 -q) = 2.20

0.15q +1.60 = 2.20 . . . . . . . simplify

0.15q = 0.60 . . . . . . . . subtract 1.60

q = 4 . . . . . . . . . . . divide by 0.15

16-q = 12

There are 12 dimes in the collection.

5 0

3 years ago

Suppose there are three types of consumers who attend concerts at your university’s performing arts center: students, staff, and

Alchen [17]

Answer: i. There are 140 students willing to pay $20.

ii. There are 200 staff members willing to pay $35.

iii. There are 100 faculty members willing to pay $50.

Step-by-step explanation: Suppose there are three types of consumers who attend concerts at Marshall university's performing arts center: students, staff, and faculty. Each of these groups has a different willingness to pay for tickets; within each group, willingness to pay is identical. There is a fixed cost of $1,000 to put on a concert, but there are essentially no variable costs.

For each concert:

A) If the performing arts center can charge only one price, what price should it charge? What are profits at this price? B) If the performing arts center can price discriminate and charge two prices, one for students and another for faculty/staff, what are its profits?

C) If the performing arts center can perfectly price discriminate and charge students, staff, and faculty three separate prices, what are its profits?

8 0

3 years ago

Helllppppppppppppppppppppppppppppp

Georgia [21]

The equation: n - 4 = -15

Now let's solve our equation for n.

n - 4 = -15

Add 4 to both sides.

n = -11

4 0

4 years ago

2 times what equals 56

wel

This is simple division to do this you must know you multiplication. However the answer is 28 ;)

8 0

4 years ago

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