You would like to construct a 95% confidence interval to estimate today's population mean temperature, so you make a series of measurements (a random sample) throughout the day. The mean of these measurements is 59 degrees Fahrenheit, and their standard deviation is 4 degrees Fahrenheit. (a) What is the best point estimate, based on the sample, to use for the population mean? O degrees (b) For each of the following sampling scenarios, determine which distribution should be used to calculate the critical value for the 95% confidence interval for the population mean. (In the table, Z refers to a standard normal distribution, and t refers to a t distribution.) Could use

Scores on the Wechsler Adult Intelligence Scale are approximately normally distributed with 100 and σ=15. Use Table B or software to answer the following questions. What scores fall in the lowest 25% of the distribution? How high a score is needed to be in the highest 5%?

A study on the latest fad diet claimed that the amounts of weight lost by all people on this diet had a mean of 20.4 pounds and a standard deviation of 3.8 pounds.    Step 1 of 2:  If a sampling distribution is created using samples of the amounts of weight lost by 93 people on this diet, what would be the mean of the sampling distribution of sample means? Round to two decimal places, if necessary.

A population has a mean μ=79and a standard deviation σ=14. Find the mean and standard deviation of a sampling distribution of sample means with sample size  n=49.   ​(Simplify your​ answer.)

[b] Instruction: Solve the following problem: Records show that the performance of male college students in Mathematics in terms of final grade is 5% higher than in female college students with a corresponding standard deviations of 4.35% and 3.97%, respectively. A mathematics instructor verifies this information by having the final grades. There are 80 students, consisting of 44 females and 36 males. The following statistics are shown:   Sex Average Final Grade Male 93.45% Female 87.42% Can the mathematics instructor say that the difference between the average final grades obtained by the males and females is higher than 5%? Use 5% level of significance. b. Determine the level of significance and the direction of test.

We want to obtain a sample to estimate a population mean. Based on previous evidence, researchers believe the population standard deviation is approximately σ=26.1. We would like to be 99% confident that the estimate is within 3 of the true population mean. How large of a sample size is required?

Suppose you take a random sample of n = 80 Douglas College students and ask each student their age. You find that the mean age of students in this sample is X = 22.0375 years and the sample standard deviation is s = 3.2014 years.  Fill in the blanks (rounding to four decimal places):  The 95% confidence interval for the mean age μ of all Douglas College students is from ______ years to ______ years.

Select the correct answer below:   p-value>0.10   0.05< p-value <0.10   0.01< p-value <0.05   p-value <0.01

Tina catches a 14-pound bass.  She does not know the population mean or standard deviation.  So she takes a sample of five friends and they say the last bass they caught was 9, 12, 13, 10, and 10 pounds.  Find the t and calculate a 95% (α = .05) confidence interval.

You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is approximately σ=38.7σ=38.7. You would like to be 98% confident that your estimate is within 5 of the true population mean. How large of a sample size is required?