Question

In: Statistics and Probability

A random sample size of n=10, population μ=65, σ=19. Determine P(x<68.9) Determine P(x ≥66.9​)

A random sample size of n=10, population μ=65, σ=19.

Determine P(x<68.9)

Determine P(x ≥66.9​)

Solutions

Expert Solution

Solution :

Given that,

mean = = 65

standard deviation = = 19

n = 10

= 65

= / n = 19 10 = 6.0083

a ) P( < 68.9 )

P ( - / ) < ( 68.9 - 65 / 6.0083)

P ( z < 3.9 / 6.0083 )

P ( z <0.65)

= 0.7422

Probability = 0.7422

b ) P (    66.9 )

= 1 - P (   66.9 )

= 1 - P ( - /)   (66.9 - 65 / 6.0083)

= 1 - P( z   1.9 / 6.0083 )

= 1 - P ( z 0.32 )   

Using z table

= 1 - 0.6255

= 0.3745

Probability = 0.3745


Related Solutions

A simple random sample of size n=37 is obtained from a population with μ=65 and σ=15....
A simple random sample of size n=37 is obtained from a population with μ=65 and σ=15. ​(a) What must be true regarding the distribution of the population in order to use the normal model to compute probabilities involving the sample​ mean? Assuming that this condition is​ true, describe the sampling distribution of overbarx. ​(b) Assuming the normal model can be​ used, determine ​P(overbar x < 69.4). ​(c) Assuming the normal model can be​ used, determine ​P(overbar x ≥ 66.7​).
A simple random sample of size n=64 is obtained from a population with μ=88 and σ=24....
A simple random sample of size n=64 is obtained from a population with μ=88 and σ=24. ​(a) Describe the sampling distribution of x. is it 1,2,3,4, or 5? 1. The distribution is skewed right. 2. The distribution is approximately normal. 3. The distribution is uniform. 4. The distribution is skewed left. 5. The shape of the distribution is unknown.    Find the mean and standard deviation of the sampling distribution of x. Ux= Ox= ​(b) What is P (x>91.75) ? Round...
A simple random sample of size n=64 is obtained from a population with μ=77 σ=24. ​(a)...
A simple random sample of size n=64 is obtained from a population with μ=77 σ=24. ​(a) Describe the sampling distribution of x ​(b) What is P (x > 80.75)​? ​(c) What is P (x ≤ 70.25)​? ​(d) What is P (74.6<x<83.3​)?
A simple random sample of size n=49 is obtained from a population with μ=78 and σ=14....
A simple random sample of size n=49 is obtained from a population with μ=78 and σ=14. ​ (b) What isP (x>81)​? ​(c) What is (P x≤73​)? ​ (d) What is P( 76.8 less than x overbar less than 81.2)
A normal distributed population has parameters μ=112.2 and σ=23.9. If a random sample of size n=98...
A normal distributed population has parameters μ=112.2 and σ=23.9. If a random sample of size n=98 is selected, What is the mean of the distribution of sample means? μ¯x= What is the standard deviation of the distribution of sample means? Round to two decimal places. to find answer σ¯x=
Suppose a simple random sample of size n=36 is obtained from a population with μ=81and σ=24....
Suppose a simple random sample of size n=36 is obtained from a population with μ=81and σ=24. ​(a) Describe the sampling distribution of barx (mean and standad deviation). ​(b) What is P (barx>85​)? (c) What is P (barx≤71​)? ​(d) What P (75.8<barx<90.6​)?
A simple random sample has a sample size of n = 65. Given the population is...
A simple random sample has a sample size of n = 65. Given the population is normally distributed, find the critical value ta/2 corresponding to a 99% confidence level. a) 2.678 b) 2.575 c) 2.000 d) 2.660
A random sample of size n = 55 is taken from a population with mean μ...
A random sample of size n = 55 is taken from a population with mean μ = −10.5 and standard deviation σ = 2. [You may find it useful to reference the z table.] a. Calculate the expected value and the standard error for the sampling distribution of the sample mean. (Negative values should be indicated by a minus sign. Round "expected value" to 1 decimal place and "standard error" to 4 decimal places.) b. What is the probability that...
A simple random sample of size n = 15 is obtained from a population with μ...
A simple random sample of size n = 15 is obtained from a population with μ = 97 and σ = 23. Enter your answer as an area under the curve with 4 decimal places. P(x⎯⎯⎯ ≤ 94)
A random sample of size n = 50 is taken from a population with mean μ...
A random sample of size n = 50 is taken from a population with mean μ = −9.5 and standard deviation σ = 2. [You may find it useful to reference the z table.] a. Calculate the expected value and the standard error for the sampling distribution of the sample mean. (Negative values should be indicated by a minus sign. Round "expected value" to 1 decimal place and "standard deviation" to 4 decimal places.) Expected Value= Standard Error= b. What...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT