An elapsed time of 3 hours and 56 minutes ends at 11:31 what’s the start time?

The mean of a population is 74 and the standard deviation is 15. The shape of the population is unknown. Determine the probabili

Lena [83]

Answer:

a) 0.0548 = 5.48% probability of a random sample of size 36 yielding a sample mean of 78 or more.

b) 0.9858 = 98.58% probability of a random sample of size 150 yielding a sample mean of between 71 and 77.

c) 0.5793 = 57.93% probability of a random sample of size 219 yielding a sample mean of less than 74.2

Step-by-step explanation:

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

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score 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 p-value, 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.

The mean of a population is 74 and the standard deviation is 15.

This means that $\mu = 74, \sigma = 15$

Question a:

Sample of 36 means that $n = 36, s = \frac{15}{\sqrt{36}} = 2.5$

This probability is 1 subtracted by the pvalue of Z when X = 78. So

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

By the Central Limit Theorem

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

$Z = \frac{78 - 74}{2.5}$

$Z = 1.6$

$Z = 1.6$ has a pvalue of 0.9452

1 - 0.9452 = 0.0548

0.0548 = 5.48% probability of a random sample of size 36 yielding a sample mean of 78 or more.

Question b:

Sample of 150 means that $n = 150, s = \frac{15}{\sqrt{150}} = 1.2247$

This probability is the pvalue of Z when X = 77 subtracted by the pvalue of Z when X = 71. So

X = 77

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

$Z = \frac{77 - 74}{1.2274}$

$Z = 2.45$

$Z = 2.45$ has a pvalue of 0.9929

X = 71

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

$Z = \frac{71 - 74}{1.2274}$

$Z = -2.45$

$Z = -2.45$ has a pvalue of 0.0071

0.9929 - 0.0071 = 0.9858

0.9858 = 98.58% probability of a random sample of size 150 yielding a sample mean of between 71 and 77.

c. A random sample of size 219 yielding a sample mean of less than 74.2

Sample size of 219 means that $n = 219, s = \frac{15}{\sqrt{219}} = 1.0136$

This probability is the pvalue of Z when X = 74.2. So

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

$Z = \frac{74.2 - 74}{1.0136}$

$Z = 0.2$

$Z = 0.2$ has a pvalue of 0.5793

0.5793 = 57.93% probability of a random sample of size 219 yielding a sample mean of less than 74.2

5 0

3 years ago

A customer is late paying their renewal registration fee. The renewal registration fee is $142.16 and the late fee is 63% of the

Andre45 [30]

$124.56 because if you have 63% you change it to a decimal so it is not .63 and you multiply it by 146.16 and then add the 35 you get 124.56

8 0

3 years ago

A packing crate can hold 205 avocados. There were 7000 avocados picked at a large grove. The owner has 36 packing crates. Does h

larisa [96]

First, you would have to divide 7000 by 205. This gives you 34 & a remainder. The owner can't pack parts of a crate so yes he does because he only has 34 full crates to ship. Leaving him with 2 extra crates left.

6 0

3 years ago

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A wheel for a game is to be made by dividing a circular disk into six equal pie-shaped wedges and numbering them from 1 to 6. in

arlik [135]

Answer:

720

Step-by-step explanation:

For the first wedge, you have 6 numbers to choose from .

For the second wedge , you have 5 numbers to choose from .

For the 3rd wedge , you have 4 numbers to choose from .

For the 4th wedge , you have 3 numbers to choose from .

For the 5th wedge , you have 2 numbers to choose from .

For the 6th wedge , you have 1 number to choose from .

Conclusion: this numbering can be done in:

6×5×4×3×2×1 = 720

Note :

Generally ,we write 6×5×4×3×2×1 as 6! and we read it 6 factorial.

6 0

2 years ago

Find the area of the figure.

Sergio039 [100]

Answer:

24 units^2

Step-by-step explanation:

bc=6

ab=8

area of a triangle: b*l/2

6*8/2=24

3 0

2 years ago

Read 2 more answers