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Use empirical rule
Plugin given values
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the amount of sleep per night of us.adults follows a normal distribution with mean 7.5 hours...
The results of a national survey showed that on average, adults sleep 6.7 hours per night. Suppose that the standard deviation is 1.9 hours and that the number of hours of sleep follows a bell-shaped distribution. If needed, round your answers to two decimal digits. (a) Use the empirical rule to calculate the percentage of individuals who sleep between 2.9 and 10.5 hours per day. Enter your answer as a percentage. (b) What is the z-value for an adult who...
The results of a national survey showed that on average, adults sleep 6.6 hours per night. Suppose that the standard deviation is 1 hour and that the number of hours of sleep follows a bell-shaped distribution. If needed, round your answers to two decimal digits. If your answer is negative use "minus sign". (a) Use the empirical rule to calculate the percentage of individuals who sleep between 4.6 and 8.6 hours per day. Enter your answer as a percentage. (b)...
The time a student sleeps per night has a normal distribution with mean 6.2 hours and a standard deviation of 0.5 hours. Find the 32nd percentile of the sleeping time of students.
The number of hours of sleep in a night is normally distributed in adults, with a mean of 7.2 hours and a standard deviation of 1.7 hours. Suppose a randomly selected adult sleeps 7.3 hours in a night. What percentile are they - that is, what percentage of adults do they sleep more than?
The number of hours adults sleep per night is normally distributed with a mean of 7.3 hours. Aussum that the standard devation is unknown. question: if 70% of adults sleep more than 6.5 hours per night, what is the variance? (remember the label)
The time a student sleeps per night has a distribution with mean 5.1 hours and a standard deviation of 0.4 hours. Find the probability that average sleeping time for a randomly selected sample of 30 students is more than 5 hours per night. (keep 4 decimal places)
Based on a random sample of 1040 adults, the mean amount of sleep per night is 8.37 hours. Assuming the population standard deviation for amount of sleep per night is 2.7 hours, construct and interpret a 95% confidence interval for the mean amount of sleep per night. A 95% confidence interval is (DD (Round to two decimal places as needed.)
Based on a random sample of 1160 adults, the mean amount of sleep per night is 8.49 hours. Assuming the population standard deviation for amount of sleep per night is 3.6 hours, construct and interpret a 95% confidence interval for the mean amount of sleep per night. A 95% confidence interval is (_____,_______). (Round to two decimal places as needed.)
The distribution of hours of sleep per week night, among college students, is found to be Normally distributed, with a mean of 6.5 hours and a standard deviation of 1 hour. What range contains the middle 95% of hours slept per week night by college students (a) 5.5 and 7.5 hours per week night (b) 4.5 and 7.5 hours per week night (c) 4.5 and 8.5 hours per week night 3.19
Based on a random sample of 1080 adults, the mean amount of sleep per night is 8.41 hours. Assuming the population standard deviation for amount of sleep per night is 3.8hours, construct and interpret a 90% confidence interval for the mean amount of sleep per night. A 90% confidence interval is (nothing,nothing). (Round to two decimal places as needed.)