Find confidence interval for population mean.

The principal randomly selected six students to take an aptitude test. Their scores were:

71.5     80.4    77.1 86.5    82.1 72.3

Determine a 90% confidence interval for the mean score for all students. Round to 2 decimal places.

I have a three part questions for grade 7 students:

1. Explain briefly the meaning of energy crisis

2. What are the consequences of using fossil fuels excessively for all of our daily activities?

3. What alternatives can be exploited to avoid over reliance on fossil fuels?

What answers and explanation i can give to grade 7 students?

Of the ten students who received an "A+" in a class during the fall 2019 semester, three were sophomores, two were juniors, and one was a senior (the remaining student(s) were in their first year). the teacher believes four of the ten students are strong candidates for TA positions. Determine the probability the four candidates include exactly one student from each year in college.

An instructor who taught two sections of MTH132, with 20 and 30 students respectively. The instructor randomly select 15 students for a field trip. 1. What is the chance that exactly 10 of them are from the 2nd section?

2. What is the chance that at least 10 of them are from the 2nd section?

3. What is the chance that at least 10 of them are from the same section?

they survey a sample of n= 25 music major students. participants respond to a measure of creativity and the average score for the sample is M=64. it is known that the distribution of creativity scores for the population of college students is normal with m=53. if the standard deviation is 40, it is the result sufficient to conclude that there is a significant difference?

Fail to reject or reject null hypothesis?

significant difference in creativity score or no significant difference ?

In the last decade, only 50.4% of high school students in Tampa’s school district graduated high school. Aiko believes her high school in St. Petersburg has a higher graduation rate. She collects a random sample of 54 former students of her high school and found that 33 of them graduated. Test Aiko’s belief using a significance level of 0.05.

The business college computing center wants to determine the proportion of business students who have laptop computers. If the proportion exceeds 30%, then the lab will scale back a proposed enlargement of its facilities. Suppose 250 business students were randomly sampled and 75 have laptops. Test if the proportion exceeds 30%. Use significant level alpha: 0.05 ( p value Method)

A random sample of 13 students were asked how long it took them to complete a certain exam. The mean length of time was 105.6 minutes, with a standard deviation of 71.7 minutes. Find the lower bound of the 90% confidence interval for the true mean length of time it would take for all students to complete the exam.

Round to one decimal place (for example: 108.1)

The distribution of weights of a large group of high school students is normally distributed with mean 55 kg and standard deviation 5 kg. Which of the following is true?

a.about 2.5% will be below 40 kg

b.about 16% of the students will be over 65 kg

c.half of them can be expected to weigh less than 55kg

d.about 2.5% will weigh more than 60 kg

23. Claim: A school being in an Urban or Suburban location is independent of how many students score proficient in Reading and Math. Data: Students are randomly selected from various schools. The number proficient in reading and math is tabulated below. ? Is this evidence at the level of significance α = 0.01 to refute the claim?

Location Reading Math

Urban 45 40

Suburban 65 61