Statistics and Probability Answers

A sample of 10 observations is selected from a normal population for which the population standard deviation is known to be 5. The sample mean is 20. (a) Determine the standard error of the mean. (b) Determine the 95% confidence interval for the population mean

in the country of chad infant mortality due to malaria has been greatly reduced thanks to insecticde treated bed nets. the percentage 'p' of insecticide remaining in treated bed net t years since the bed is first used can be modeled byt the following linear equation p(t)= -9.42t+ 99.4. is the y-intercept applicable why or why not? and interpret the slope?

A Lottery consists of 200 lottery tickets. There are 30 tickets with some prize and only three of them with the grand prize. Alex bought 10 tickets. Find the probability that he won at least one grand prize if he won 5 prizes.

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Assuming the population variances are known, the population variance of the difference between two sample means is
A) the sum of the two means.
B) the sum of the variances for each population.
C) the sum of the standard deviations for each population.
D) the sum of the sample sizes for each population.

the number of vehicles entering through a university's making gate is 5 in 60 minutes.find the probability that in 90 minutes:(a)no vehicle will enter.(b)at least 2 vehicles will enter.(c)at most 3 vehicles will enter.(d)less than four vehicles will enter.(e)more than 3 vehicles will enter.(f)exactly 5 vehicles will enter

the scores of students is a statistics test is known to be normally distributed with mean 60% and variance 16.Compute the proportion of students who scored:(a) more than 60%. (b)below 58%.(c)between 56%and 60%.(e)if 10% of the students got distinction,what is the max mark of distinction?

a player has 30% of scoring a penalty kick in a soccer match,if there are 9 penalty kicks during a soccer match,find the probability that the player will:
a)score none.(b)score at most 3.(c)score less than 4.(d)score at least 2.(e)score more than 3.(f)score exactly 5 penalty kicks.

There are several types of sampling strategies. These include: simple random sampling, systematic random sampling, stratified random sampling (stratified proportionately of disproportionately). What are the primary characteristics that distinguish these approaches? And, conversely, what characteristic makes each of these approaches similar?

Please indicate a real-life situation to which geometric distribution could be applied, and explain why.

Give a detailed example.

Find the indicated probability Weekly salaries of teachers in one state are normally distrubuted with a mean of $490 and a standard deviation of $45. What is the probblity that a randomly selected teacher earns more than $525 a week?