Assume that a student’s score in a course follows normal distribution. A sample of 10 students’ scores is as follow: 65, 32, 78, 90, 45, 66, 78, 55, 24, 87.

(a) Find the sample mean and sample standard deviation for this sample.

(b) Find a 90% confidence interval for the mean score of all the students. Interpret the result.

(c) Test, at significance level 10%, if the average score is lower than 70.

How are your grades? In a recent semester at a local university, 300 students enrolled in both Statistics I and Psychology I. Of these students, 83 got an A in statistics, 75 got an A in psychology, and 49 got an A in both statistics and psychology. Round the answers to four decimal places, as needed.

A) Find the probability that a randomly chosen student got an A in statistics or psychology or both.
B) Find the probability that a randomly chosen student did not get an A in statistics.

A typical college student spends an average of 2.55 hours a day using a computer. A sample of 13 students at The University of Findlay revealed the sample mean of 2.70 hours and sample standard deviation of 0.51 hours.

Can we conclude that the mean number of hours per day using the computer by students at The University of Findlay is the same as the typical student’s usage? Use the five step hypothesis testing procedure and the 0.05 significance level.

A group of students estimated the length of one minute without reference to a watch or​ clock, and the times​ (seconds) are listed below. Use a 0.10 significance level to test the claim that these times are from a population with a mean equal to 60 seconds. Does it appear that students are reasonably good at estimating one​ minute?

80, 90, 49, 75, 52, 33, 70, 71, 72, 58, 75, 82, 100, 98, 77

1. A social science researcher collected data from a random sample of 400 students at a large university and found that, on average, they belonged to 2.6 campus organizations. The standard deviation σ for the population is 1.8.

1. Using these data, construct a 95% confidence interval for µ, the mean number of campus organizations belonged to by the population of students at this university.

2. Write a sentence to interpret your confidence interval, making sure to provide all the important information.

5 students attending an exam. Let Si be the event of student i passes an exam. S1 and S2 may or may not be independent of each other. Let random variable X be total number of students who pass the exam. P(S1) = P(S2) = 2/3. X = 0, 1, 2, 3, 4, 5.

1) E(X)

2) What is the min and max of var(X)

1. A college statistics instructor claims that the mean age of college statistics students is 24. A random sample of 116 college statistics students revealed a mean age of 22.7. The population standard deviation is known to be 5.68 years. Test his claim at the 0.05 level of significance.

1. State the hypotheses and identify the claim.

2. Find the critical value(s)

3. Compute the test value.

4. Make the decision to reject or not reject the null hypothesis.

5. Summarize the results.

Consider a distribution of student scores that is Normal with a mean of 288 and a standard deviation of 38.

1. What is the normalized value (z-score) of a score of 300?
2. What is the proportion of students with scores greater than 300?
3. What is the proportion of students with scores between 290 and 320?
4. Using the 68-95-99.7 rule, what are the two scores symmetrically placed around the mean that would include 68% of the observations?

A survey of high school students revealed that the numbers of soft drinks consumed per month was normally distributed with mean 25 and standard deviation 15. A sample of 36 students was selected. What is the probability that the average number of soft drinks consumed per month for the sample was between 26.2 and 30 soft drinks?

Write only a number as your answer. Round to 4 decimal places (for example 0.0048). Do not write as a percentage.

The nursing students are discussing patient safety during a clinical experience. The clinical instructor mentions that the hospital is interested in addressing The Joint Commission’s patient safety goals are associated with the use of health information technology (Learning Objective: 6).

Which Joint Commission safety goals are directly related to health information technology?

How can a group of nursing students impact the recommendations concerning alarm safety cited by the Joint Commission?