Let x be a normal random variable with mean 35 and standard deviation 2.
a. Find P(30 < x < 38).
.9270
b. Find P(x > 34).
.6915
c. Find P(x = 36).
0
d. Find the area under the distribution of x to the left of 31.
.0228
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Allegiant Airlines charges a mean base fare of $87. In addition, the airline charges for making a reservation on its website, checking bags, and inflight beverages. These additional charges average $37 per passenger. Suppose a random sample of 50 passengers is taken to determine the total cost of their flight on Allegiant Airlines. The population standard deviation of total flight cost is known to be $38. Use z-table.
a. What is the population mean cost per flight?
b. What is the probability the sample mean will be within $10 of the population mean cost per flight (to 4 decimals)?
c. What is the probability the sample mean will be within $5 of the population mean cost per flight (to 4 decimals)?
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In: Math
What is the difference between expected payoff under certainty and expected payoff under risk?
Explain the basic decision environment categories
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Assume that when adults with smartphones are randomly selected, 39% use them in meetings or classes. If 5 adults smartphone users are randomly selected, find the probability that exactly 2 of them use their smartphones in meetings or classes.
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1. Given sample data: 61.2, 61.9, 62.8, 63.1, 64.0, 64.3, 64.9,
65.5, 66.3 and 67.9,
test H0: m £ 62.89 versus H1:
m > 62.89 at a = 0.05
2. Test H0: π = 0.25 versus HA: π ¹ 0.25 with p = 0.33 and n = 100 at alpha = 0.05 and 0.10.
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Thirty percent of all customers who enter a store will make a purchase. Suppose 10 customers enter the store, and that they make independent purchasing decisions.
(a) Let X be the number, out of the 10 customers in the store, who will make a purchase. Write the binomial probability density function for this situation.
(b) Use the binomial distribution to calculate the probability exactly 5 customers make a purchase.
(c) Find the probability that 4 or fewer customers make a purchase.
(d) Find the probability that 7 or more customers make a purchase.
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Pharmaceutical companies promote their prescription drugs using television advertising. In a survey of 75 randomly sampled television viewers, 12 indicated that they asked their physician about using a prescription drug they saw advertised on TV.
Develop a 90% confidence interval for the proportion of viewers who discussed a drug seen on TV with their physician. (Round your answers to 3 decimal places.)
Is it reasonable to conclude that 26% of the viewers discuss an advertised drug with their physician?
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sampling, variables, hypothesis testing, z scores, and standard deviation
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If the probability that a certain tennis player will serve an ace is 1/ 6 , what is the probability that he will serve exactly four aces out of six serves? (Assume that the six serves are independent. Round your answer to four decimal places.)
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Is there enough evidence to conclude that the average salary at the Company A is LESS than the average salary at the Company B ( α = 0.04)?
Average Salary | |
Company A | Company B |
$58,000 | $47,000 |
$59,000 | $74,000 |
$60,000 | $56,000 |
$73,000 | $55,000 |
$63,000 | $65,000 |
$62,000 | $52,000 |
$59,000 | $68,000 |
$55,000 | $63,000 |
$61,000 | $66,000 |
$60,000 | $66,000 |
$54,000 | $57,000 |
$66,000 | $59,000 |
$61,000 | $58,000 |
$48,000 | $63,000 |
$61,000 | $66,000 |
$60,000 | $62,000 |
$54,000 | $62,000 |
$67,000 | $53,000 |
$63,000 | $46,000 |
$53,000 | $54,000 |
$55,000 | $65,000 |
$52,000 | $61,000 |
$49,000 | $72,000 |
$56,000 | $45,000 |
$59,000 | $70,000 |
$61,000 | $59,000 |
$53,000 | $67,000 |
$50,000 | $65,000 |
$61,000 | $63,000 |
$53,000 | $63,000 |
$58,000 | $65,000 |
$64,000 | $68,000 |
$58,000 | $56,000 |
$52,000 | $57,000 |
$59,000 | $73,000 |
$57,000 | $70,000 |
$52,000 | $62,000 |
$52,000 | $57,000 |
$62,000 | $64,000 |
$67,000 | $70,000 |
$56,000 | |
$55,000 | |
$61,000 | |
$61,000 | |
$60,000 | |
$55,000 |
In: Math
The lengths of pregnancies in a small rural village are normally
distributed with a mean of 270 days and a standard deviation of 15
days.
In what range would you expect to find the middle 98% of most
pregnancies?
Between _____and ____.
If you were to draw samples of size 36 from this population, in
what range would you expect to find the middle 98% of most averages
for the lengths of pregnancies in the sample?
Between ____and _____ .
Enter your answers as numbers. Your answers should be
accurate to 1 decimal places.
Please only respond to this question if you can do so accurately and entirely.
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For each situation, perform a hypothesis test for the population mean. Be sure to show the null hypothesis H0, the alternative hypothesis H1, the P-level you get from TTest, the result of the test (i.e. reject / do not reject H0) and the conclusion (interpret the result in English).
A Jedi sage would like proof that Jedi trainees have a higher level of midichlorians than non-Jedis. Non-Jedis have a mean midichlorian level of 2500. A random sample of 25 Jedi trainees have a sample mean midichlorian level of 2875, with a sample standard deviation of 1050. Is this adequate evidence at the α = 0.05 level of certainty that Jedi trainees have higher midichlorian levels than non-Jedis?
H0:
H1:
P-level:
Result:
Conclusion:
In: Math
a politician claims that the mean salary for managers
in his State is more than the national mean, $82,000.00. Assume the
population is normally distributed and the population deviation is
$9500.00. The salaries(in dollars) for a random sample of 30
managers in the state are listed. At a=0.07, is there enough
evidence to support the claim?
the dollar amounts are:$73,747.00, $87,299.00, $77,242.00,
$72,623.00, $80,753.00, $83,263.00, $96,365.00, $93,988.00,
$87,831.00, $97,484.00, $74,216.00, $71,883.00, $83,884.00,
$89,409.00, $78,373.00, $75,138.00, $83,274.00, $91,670.00,
$92,903.00, $74,575.00, $77,973.00, $73,195.00, $83,379.00,
$73,439.00, $95,380.00, $98,473.00, $99,111.00, $71,077.00,
$75,251.00, $74,547.00.
I also need the standardized test statistic and the p-value as
well
please find the standardized test statistic and the p- value.
In: Math
Suppose you perform the following multiple regression: Y = B0 + B1X1 + B2X2 + B3X3. You find that X1 and X3 have a near perfect correlation. How would you conclude on the utility of your regression result? This is a problem of multicollinearity which renders the entire regression invalid. This is a problem of multicollinearity which nevertheless does not invalidate the utility of the model as a whole This is NOT a regression problem and inferences made using the model and the respective coefficients remain valid. This is a problem of multicollinearity. However inferences made concerning the individual contribution of the model coefficients remain valid
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