The standard deviation of a sample proportion p^ gets smaller as the sample size n increases. If the population proportion is p = 0.45, how large a sample is needed to reduce the standard...

The standard deviation of a sample proportion p^ gets smaller as the sample size n increases. If the population proportion is p = 0.45, how large a sample is needed to reduce the standard...

Typographic errors in a text are either nonword errors (as when "the" is typed as "teh") or word errors that result in a real but incorrect word. Spell-checking software will catch...

a machine fills cough syrup bottles. the distribution for the amount of cough syrup filled by the machine follows a normal distribution with a mean of 12.2 ounces and a standard devation of 0.10 ounces...

An educational psychologist wishes to know the mean number of words a third grader can read per minute. She wants to make an estimate at the 80% level of confidence. For a sample of 448 third graders,...

Assuming you are rolling a pair of fair six-sided dice so that your random variable X is the sum of the two up faces. Recall that the population mean and standard deviation are: μX=7, σX= 1.707825 If...

Gocerment agencies carefully monitor water quality and it's effect on wetlands. Of particular concern is the concentration of nitrogen in water draining from fertilizer lands. Twenty-eight samples...

Suppose a lie detector test has the following properties.If the suspect is telling the truth,the lie detector will correct say so with probability 0.85.if the suspect is lying ,it will correctly identify...

What units would you expect to see if you were calculating the sample STANDARD DEVIATION of sales from a convenient store?

he amount of money that a student at harvard university carries on his/her person is normally distributed with a mean of $25 and a standard deviation of $5. What is the probability that a randomly...

A) What is the chance of obtaining a birth weight of 141 oz or heavier when sampling birth records at random? B) What is the chance of obtaining a birth weight of 120 or lighter?

I'm learning statistics all over again. I need to see how to find the area under the curve using z tables.

in a standard normal distribution find the area under the cure for z -scores less than -1.23 round to the 4 decimal places?

A bank manager decides to study waiting times of customers for teller service at the noon lunch hour (noon to 1pm). He selects one customer every 20 minutes to measure the time the customer enters...

A computer terminal can pick up an erroneous signal from the keyboard that does not show up on the screen. This creates a silent error that is difficult to detect. Assume that for a particular...

math sat scores are normally distributed with mean 500 and standard deviation of 100 ten students are selected at random what is the probability that at least one scored 650 or better? please...

Suppose 40% of the restaurants in a certain part of a town are in violation of the health code. A health inspector randomly selects seven of the restaurants for inspection.

A test of the null hypothesis H0: μ = μ0 gives test statistic z = 1.85. (Round your answers to four decimal places.)

A bus starts with five people and makes 10 stops . assume that passengers are equally likely to get off at any stop. A)describe the sample space and calculate the number of different outcomes...

The amounts of nicotine in a certain brand of cigarette are normally distributed with a mean of 0.933 g and a standard deviation of 0.308 g. Find the probability of randomly selecting a cigarette...

assume that x and y are independent with x ~EXP(2) and Y~Exp(1) Find the probability that the roots of the equation h(t)=0 are real where h(t)=t^2+2tx+y Could you please help...

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