Question

In: Statistics and Probability

The amount of factor X is human blood is believed to follow a normal curve with...

The amount of factor X is human blood is believed to follow a normal curve with a mean of 4500 units and a standard deviation of 1000 units. What is the range of test scores that will cover the middle 75% of the population?

Solutions

Expert Solution

Given that,

mean = = 4500

standard deviation = =1000

middle 75% of score is

P(-z < Z < z) = 0.75

P(Z < z) - P(Z < -z) = 0.75

2 P(Z < z) - 1 = 0.75

2 P(Z < z) = 1 + 0.75 = 1.75

P(Z < z) = 1.75 / 2 = 0.875

P(Z <1.15 ) = 0.875

z  ± 1.15 using z table

Using z-score formula  

x= z * +

x= -1.15 *1000+4500

x= 3350

z = 1.15

Using z-score formula  

x= z * +

x= 1.15 *1000+4500

x= 5650

range= 3350 to 5650


Related Solutions

Human Resource: It is believed that first-year salaries for newly fresh graduates follow a normal distribution...
Human Resource: It is believed that first-year salaries for newly fresh graduates follow a normal distribution with a standard deviation of RM2,500. A random sample of 29-B newly fresh graduates was chosen. Find the probability that the sample standard deviation is more than RM3,000. Find the probability that the sample standard deviation is less than RM1,500.
Diastolic blood pressure measurements on American men ages 18-44 years follow approximately a normal curve with...
Diastolic blood pressure measurements on American men ages 18-44 years follow approximately a normal curve with μ = 81 mm Hg and σ =11 mm Hg. The distribution for women ages 18-44 is also approximately normal with the same SD but with a lower mean, μ =75 mm Hg. Suppose we are going to measure the diastolic blood pressure of n randomly selected men and n randomly selected women in the age group 18-44 years. Let E be the event...
The amount of a loss, Y, is assumed to follow a Normal distribution with a mean...
The amount of a loss, Y, is assumed to follow a Normal distribution with a mean of ? and a variance of ?^2. The median of Y is 56.5 and the 59.1-th percentile of Y is 56.776. Determine P(Y > 60 ).
Find the slope of the normal line to the curve described by (x + y) ^...
Find the slope of the normal line to the curve described by (x + y) ^ (1/2) = xy ^ 2 + e ^ x at the point (0,1)
MULTIPLE CHOICE QUESTIONS QUESTION 1 Most of the volume of normal human blood is composed of:...
MULTIPLE CHOICE QUESTIONS QUESTION 1 Most of the volume of normal human blood is composed of: 1. red cells 2. hemoglobin 3. plasma 4. white cells QUESTION 2 Also called white blood cells 1. Thrombocytes 2. Erythrocytes 3. Platelets 4. Leukocytes QUESTION 3 Platelets are formed from what type of cell? 1. Melanocytes 2. Macrophages 3. Astrocytes 4. Megakaryocytes QUESTION 4 Which of the following statements is true regarding the ABO blood system? 1. People who have the A antigen...
Let the random variable X follow a normal distribution with a mean of μ and a...
Let the random variable X follow a normal distribution with a mean of μ and a standard deviation of σ. Let 1 be the mean of a sample of 36 observations randomly chosen from this population, and 2 be the mean of a sample of 25 observations randomly chosen from the same population. a) How are 1 and 2 distributed? Write down the form of the density function and the corresponding parameters. b) Evaluate the statement: ?(?−0.2?< ?̅1 < ?+0.2?)<?(?−0.2?<...
Find the equations for the tangent line and the normal line to the curve x^2 +...
Find the equations for the tangent line and the normal line to the curve x^2 + arcsin(x + y − 1) = y^2sqrt(8x) at the point (2, −1)..
The test grades in some class follow a normal distribution (we will call it X) with...
The test grades in some class follow a normal distribution (we will call it X) with σ = 8. Use this information (and the chart!) to answer the following questions: (a) If there is a 60% chance that a student scores higher than a 75, find µ, the average test grade for this class. (b) Using the µ you found in part (a), determine P(72 ≤ X ≤ 90).
let the random variable x follow a normal distribution with μ = 50 and σ2 =...
let the random variable x follow a normal distribution with μ = 50 and σ2 = 64. a. find the probability that x is greater than 60. b. find the probability that x is greater than 35 and less than 62 . c. find the probability that x is less than 55. d. the probability is 0.2 that x is greater than what number? e. the probability is 0.05 that x is in the symmetric interval about the mean between...
et the random variable x follow a normal distribution with μ = 50 and σ2 =...
et the random variable x follow a normal distribution with μ = 50 and σ2 = 64. a. find the probability that x is greater than 60. b. find the probability that x is greater than 35 and less than 62 . c. find the probability that x is less than 55. d. the probability is 0.2 that x is greater than what number? e. the probability is 0.05 that x is in the symmetric interval about the mean between...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT