7.3.36 : Question Help Randomly selected students participated in an experiment

Question

7.3.36 : Question Help Randomly selected students participated in an experiment to test their ability to determine when one minute (or sixty seconds) has passed. Forty students yielded a sample mean of 60.1 seconds. Assuming that = 10.1 seconds, construct and interpret a 90% confidence interval estimate of the population mean ofal students. Click here to view a t distribution table. Click here to view page 1 of the standard normal distribution table. Click here to view page 2 of the standard normal distribution table. le. What is the 90% confidence interval for the population mean ? (Type integers or decimals rounded to one decimal place as needed.)

Explanation / Answer

Solution:

We use z test here, since sample size is greater than 40. Also is known.

= 10.1

sample mean= x bar = 60.1

= 0.10

/2= 0.10/2 = 0.05

z/2 = 1.645

Interval will be,

x bar - z/2./n < < x bar + z/2./n
60.1 - 1.645*(10.1/40) < < 60.1 + 1.645*(10.1/40)
60.1 - 2.63< < 61.1 + 2.63

57.47 < < 62.73

We can say that at 90%, lies between 57.47 and 62.73

So it is likely that students estimates have a mean that is reaonably close to 60 seconds.

Related Questions

Navigate

• Browse (All)
• Browse 7
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.