Question

Suppose a geyser has a mean time between eruptions of 61 minutes. Let the interval of...

Suppose a geyser has a mean time between eruptions of 61 minutes. Let the interval of time between the eruptions be normally distributed with standard deviation 20 minutes.Complete parts ​(a) through ​(e) below.

​(e) What might you conclude if a random sample of 35 time intervals between eruptions has a mean longer than 69 ​minutes? Select all that apply.

a)The population mean may be less than 61

b)The population mean may be greater than 61

c)The population mean must be more than 61,since the probability is so low.

d)The population mean cannot be 61,since the probability is so low.

e)The population mean is 61 and this is an example of a typical sampling result.

f)The population mean is 61 and this is just a rare sampling.

g)The population mean must be less than 61, since the probability is so low.

Homework Answers

Answer #1

Let T be the interval of time between the eruptions.

By Central limit theorem, the sample mean follows Normal distribution with mean 61 minutes and standard deviation = 20/ = 3.38

Probability that mean longer than 69 ​minutes = P( > 69)

= P(Z > (69 - 61)/3.38)

= P(Z > 2.37]

= 0.0089

The probability is so low. So, the population mean may be greater than 61 (near to 69)

So, the following options are valid.

b)The population mean may be greater than 61

c)The population mean must be more than 61,since the probability is so low.

d)The population mean cannot be 61,since the probability is so low.

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Suppose a geyser has a mean time between eruptions of 75 minutes. Let the interval of...
Suppose a geyser has a mean time between eruptions of 75 minutes. Let the interval of time between the eruptions be normally distributed with standard deviation 26 minutes. Complete parts ​(a) through ​(e) below ​ (a) What is the probability that a randomly selected time interval between eruptions is longer than 87 ​minutes? ​(b) What is the probability that a random sample of 13 time intervals between eruptions has a mean longer than 87 ​minutes? ​(c) What is the probability...
Suppose a geyser has a mean time between eruptions of 79 minutes. Let the interval of...
Suppose a geyser has a mean time between eruptions of 79 minutes. Let the interval of time between the eruptions be normally distributed with standard deviation 22 minutes. Complete parts ​(a) through ​(e) below. ​(a) What is the probability that a randomly selected time interval between eruptions is longer than 90 ​minutes? The probability that a randomly selected time interval is longer than 90 minutes is approximately nothing. ​(Round to four decimal places as​ needed.) ​(b) What is the probability...
Suppose a geyser has a mean time between eruptions of 86 minutes. Let the interval of...
Suppose a geyser has a mean time between eruptions of 86 minutes. Let the interval of time between the eruptions be normally distributed with standard deviation 19 minutes. Complete parts ​(a) through ​(e) below. (a) What is the probability that a randomly selected time interval between eruptions is longer than 94 minutes? (b) What is the probability that a random sample of 9 time intervals between eruptions has a mean longer than 94 ​minutes? (c) What is the probability that...
Suppose a geyser has a mean time between eruptions of 86 minutes Let the interval of...
Suppose a geyser has a mean time between eruptions of 86 minutes Let the interval of time between the eruptions be normally distributed with standard deviation 26 minutes . ​(a) What is the probability that a randomly selected time interval between eruptions is longer than 99 ​minutes? ​(b) What is the probability that a random sample of 9 time intervals between eruptions has a mean longer than 99 ​minutes?
Suppose a geyser has a mean time between eruptions of 85 minutes. Let the interval of...
Suppose a geyser has a mean time between eruptions of 85 minutes. Let the interval of time between the eruptions be normally distributed with standard deviation 23 minutes. What is the probability that a random sample of 9 time intervals between eruptions has a mean longer than 96 ​minutes? The probability that the mean of a random sample of 9 time intervals is more than 96 minutes is approximately _______. ​(Round to four decimal places as​ needed.)
Suppose a geyser has a mean time between eruptions of 84 minutes. If the interval of...
Suppose a geyser has a mean time between eruptions of 84 minutes. If the interval of time between the eruptions is normally distributed with standard deviation 27 minutes A. Whats the probability that a random sample of 13 time intervals between eruptions has a mean longer than 95 minutes. B. Whats the probability that a random sample of 28 time intervals between eruptions has a mean time longer than 95 minutes. C. What effect does increasing the sample size have...
Suppose a geyser has a mean time between eruptions of 70 minutes If the interval of...
Suppose a geyser has a mean time between eruptions of 70 minutes If the interval of time between the eruptions is normally distributed with standard deviation 20 minutes answer the following questions. ​(a) What is the probability that a randomly selected time interval between eruptions is longer than 80 ​minutes? The probability that a randomly selected time interval is longer than 80 minutes is approximately?
In a sample of 500 eruptions of the Old Faithful geyser at Yellowstone National Park, the...
In a sample of 500 eruptions of the Old Faithful geyser at Yellowstone National Park, the mean duration of the eruptions was 3.32 minutes and the standard deviation was 2.09 minutes. A random sample of size 30 is drawn from this population. a. Describe the sampling distribution of the eruptions of the Old Faithful geyser. b. What is the probability that the mean duration of eruptions is between 2.5 minutes and 4 minutes?
The following are 30 time lapses in minutes between eruptions of Old Faithful geyser in Yellowstone...
The following are 30 time lapses in minutes between eruptions of Old Faithful geyser in Yellowstone National Park, recorded between the hours of 8 a.m. and 10 p.m. on a certain day, and measured from the beginning of one eruption to the beginning of the next: 68, 63, 66, 63, 61, 44, 60, 62, 71, 62, 62, 55, 62, 67, 73, 72, 55, 67, 68, 65, 60, 61, 71, 60, 68, 67, 72, 69, 65, 66 A researcher wants to...
Listed below are time intervals​ (min) between eruptions of a geyser. The​ "recent" times are within...
Listed below are time intervals​ (min) between eruptions of a geyser. The​ "recent" times are within the past few​ years, and the​ "past" times are from 1995. Does it appear that the variation of the times between eruptions has​ changed? Use a 0.05 significance level. Assume that the two populations are normally distributed. 77 86 90 91 91 93 76 96 57 62 101 87 62 89 90 92 69 84 92 95 84 86 81 96