document.write( "Question 1076812: Need help with the t and p value on this one, thank you!
\n" ); document.write( "Let x be a random variable that represents red blood cell count (RBC) in millions of cells per cubic millimeter of whole blood. Then x has a distribution that is approximately normal. For the population of healthy female adults, suppose the mean of the x distribution is about 4.66. Suppose that a female patient has taken six laboratory blood tests over the past several months and that the RBC count data sent to the patient's doctor are as follows.
\n" ); document.write( "4.9 4.2 4.5 4.1 4.4 4.3
\n" ); document.write( "(i) Use a calculator with sample mean and standard deviation keys to find x and s. (Round your answers to two decimal places.)
\n" ); document.write( "x =
\n" ); document.write( "4.40
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\n" ); document.write( "Correct: Your answer is correct.
\n" ); document.write( "s =
\n" ); document.write( ".28
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\n" ); document.write( "Correct: Your answer is correct.\r
\n" ); document.write( "\n" ); document.write( "(ii) Do the given data indicate that the population mean RBC count for this patient is lower than 4.66? Use α = 0.10.
\n" ); document.write( "(a) What is the level of significance?
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\n" ); document.write( "0.10
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\n" ); document.write( "Correct: Your answer is correct.
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\n" ); document.write( "\n" ); document.write( "State the null and alternate hypotheses.
\n" ); document.write( "H0: μ > 4.66; H1: μ = 4.66
\n" ); document.write( "H0: μ = 4.66; H1: μ > 4.66
\n" ); document.write( "H0: μ = 4.66; H1: μ ≠ 4.66
\n" ); document.write( "H0: μ = 4.66; H1: μ < 4.66
\n" ); document.write( "H0: μ < 4.66; H1: μ = 4.66
\n" ); document.write( "Correct: Your answer is correct.\r
\n" ); document.write( "\n" ); document.write( "(b) What sampling distribution will you use? Explain the rationale for your choice of sampling distribution.
\n" ); document.write( "The standard normal, since we assume that x has a normal distribution and σ is known.
\n" ); document.write( "The Student's t, since we assume that x has a normal distribution and σ is unknown.
\n" ); document.write( "The Student's t, since we assume that x has a normal distribution and σ is known.
\n" ); document.write( "The standard normal, since we assume that x has a normal distribution and σ is unknown.
\n" ); document.write( "Correct: Your answer is correct.\r
\n" ); document.write( "\n" ); document.write( "What is the value of the sample test statistic? (Round your answer to three decimal places.)
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\n" ); document.write( "-2.394
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\n" ); document.write( "Incorrect: Your answer is incorrect.
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\n" ); document.write( "\n" ); document.write( "(c) Find the P-value. (Round your answer to four decimal places.)
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Algebra.Com's Answer #691428 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Calculating the t test statistic\r
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\n" ); document.write( "\n" ); document.write( "t = (xbar - mu)/(s/sqrt(n))
\n" ); document.write( "t = (4.40-4.66)/(0.28/sqrt(6))
\n" ); document.write( "t = -2.27452618972722
\n" ); document.write( "t = -2.275\r
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\n" ); document.write( "\n" ); document.write( "The t test statistic is approximately -2.275\r
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\n" ); document.write( "\n" ); document.write( "Calculating the p value\r
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\n" ); document.write( "\n" ); document.write( "We have two basic options to calculate the p value: a) using a table or b) using a calculator\r
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\n" ); document.write( "\n" ); document.write( "Since your teacher wants it accurate to 4 decimal places, we'll have to use a calculator to get the desired accuracy. Using a TI calculator, you would type in tcdf(-99,-2.275,5) as shown below
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\n" ); document.write( "Note: Hit the 2ND key up at the top corner, then hit the VARS key. Scroll down to \"tcdf\" which is option number 6. The first two numbers \"-99, -2.275\" are the left and right bounds of the interval. Effectively this is the same as saying \"everything to the left of -2.275. The last value 5 is the degrees of freedom (df = n-1 = 6-1 = 5)\r
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\n" ); document.write( "\n" ); document.write( "Doing all that, we get the p value of roughly 0.0359934669 which rounds to 0.0360 when you round to four decimal places. \r
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\n" ); document.write( "\n" ); document.write( "Side Note: if you don't have a TI calculator, then you can use online calculators, such as this one, to calculate the p value.
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