Search
The Average weight of 25 chocolate bars selected from a normally distributed population is 200 grams with a standard deviation of 10 grams. Find the point estimate and the confidence interval using 95%confidence level.
Steps: Solution:
3.Collect and present sample evidence.
a.Collect the sample information The sample information consists of
_____(6),_______(7)and______(8).
b.Find the point estimate. The point estimate for the population
mean is ____________(9)
The Average weight of 25 chocolate bars selected from a normally distributed population is 200 grams with a standard deviation of 10 grams. Find the point estimate and the confidence interval using 95%confidence level.
Steps: Solution:
2.Specify the confidence interval criteria.
b.Determine the test statistic to be used The test statistic is ___-test(4)
to calculate the interval.
c.State the level of confidence The level of confidence is _______(5)
INTERVAL ESTIMATE
4. Suppose that the amount of time spend by working student weekly is normally distributed with the standard deviation of 25 minutes. A random sample of 125 observations is drawn and the sample mean is computed as 150 minutes. Determine the 95% confidence interval estimate of the population mean.
INTERVAL ESTIMATE
4. Suppose that the amount of time spend by working student weekly is normally distributed with the standard deviation of 25 minutes. A random sample of 125 observations is drawn and the sample mean is computed as 150 minutes. Determine the 95% confidence interval estimate of the population mean.
Directions: identify the test tool use in a certain problem
1. Hospital Infections A medical investigation claims that the average number of infections per week at a hospital in south-western Pennsylvania is 16.3. A random sample of 10 weeks had a mean number of 17.7 infections. The sample standard deviation is 1.8. Is there enough evidence to reject the investigator's claim at alpha = 0.05 ?
Type of test:
Reason/s:
two incandescent lights are chosen at random from 19 lights of which 4 are defective. Find the probability that (a) none is defective? (b) exactly one is defective?
Give the notation and area of these z score
1. above 𝑧 = −2.4
2. below 𝑧 = 0.2
3. Between 𝑧 = −2.3 𝑎𝑛𝑑
𝑧 = −0.98
4. at least 𝑧 = 0.23
5. Between 𝑧 =−1.23 𝑎𝑛𝑑 𝑧 =2
A. Areas under the Normal Curve: Find the area of the following. Then, illustrate using the
normal curve.
1. 𝑧 = 0.34
2. 𝑧 = 2.12
3. 𝑧 = −1.35
4. 𝑧 = −0.27
5. 𝑧 = 1.07
6. At least 𝑧 = −0.47
7. Between 𝑧 = 0.76 𝑎𝑛𝑑 𝑧=2.34
8. Greater than 𝑧 = 0.78
9. Less than 𝑧 = −0.67
10. Between 𝑧 =−1.52 𝑎𝑛𝑑 𝑧=0.97
Apply the Normal Curve concepts to solve each of the following. Show your complete solution
and illustration.
2. Most graduate schools of business require applicants for admission to take the Graduate
Management Admission Council’s GMAT examination. Scores on the GMAT are roughly
normally distributed with a mean of 506 and a standard deviation of 96.
a. What is the probability of an individual scoring above 520? (with illustration)
b. What is the probability of an individual scoring below 506? (with illustration)
c. What is the probability of an individual scoring from 387 to 712? (with illustration)
3. Given 𝜇=45, and 𝜎=5.5.
a. What is the raw score when 𝑧=−1.57?
b. What is the raw score when 𝑧=2.09?
c. What is the raw score when −0.48<𝑧 <1.4?
d. What is the raw score when −2.17<𝑧 <1.79?
e. What is the raw score when 𝑧=0.09?
DIRECTIONS: Solve for the z-computed value of the following. Write your answer to the
nearest hundredths. Show the complete solution.
1. x̅ = 9.2 μ = 10 σ =3 n = 68
2. x̅ = 28.3 μ = 26 σ = 4.5 n = 80
3. x̅ = 72.2 μ = 75 σ = 5.8 n = 118
4. x̅ = 49.6 μ = 52 σ = 7 n = 160
5. x̅ = 92 μ = 100 σ = 12 n = 130
