Your Questions About Sample Will
Mark asks…
A random sample of size 20 from a normal population will sample mean 42 and sample standard deviation of 6 . T?
A random sample of size 20 from a normal population will sample mean 42 and sample standard deviation of 6 . To test the hypothesis the population mean 44 at 5% level of significance , find the p-value and comment
MonroyPro answers:
H0: ? = 44
HA: ? ? 44
Sample mean = 42
Standard deviation = 6
Standard error of mean = s / ? N
Standard error of mean = 6 / ? 20
SE = 6/4.4721
Standard error of mean 1.3416
t = (xbar- ? ) / SE
t = (42-44) / 1.3416
t = -1.4907
|t| = 1.4907
At 5% level of significance, the t-critical value(with 19 degrees of freedom) is 2.093
The exact p-value cannot be computed from a t-table. |t| = 1.49 and the p-value lies between 0.10 and 0.20.
Since the p-value > 0.05 (level of significance), we do not reject the null hypothesis that the population mean is 44.
Richard asks…
Will a urine sample taken in the morning still be ok to be taken to doctors at 4pm the same day?
i have a docs appointment at 4-50 and they want me to provide a urine sample for a pregnancy test, and they want the first urine ov the day. will the sample still be ok after sitting in the pot all day? please help?
MonroyPro answers:
It should be fine, you may want to put it on ice if youre worried, I had to do a 24 hour urine collection and I had to keep it on ice.
Laura asks…
If there is sperm in a urine sample will it effect the results?
I masturbated yesterday and this morning i got up to do a urine sample i needed to do in the morning and the first part of my pee was meant for this chlamydia one and it was kinda misty im thinkin left over sperm might have got in it.
Would this effect the results of the test on the urine? and should I pour it out and re do it tomorrow or something.
MonroyPro answers:
That sounds more like a symptom of chlamydia than anything else, sorry to say that. But its apparently easy to sort out so if you do have it – no worries.
Sharon asks…
SPECIFIC HEAT PROBLEM! Which sample will end up at the highest temperature?
Three 75g samples of copper, silver, and gold are available. Each of these samples is initally at 24 degrees C, and then 2.00kJ of heat is applied to each sample. Which sample will end up at the highest temperature?
MonroyPro answers:
GOLD: 231 degrees C
Copper: 93.1
Silver: 53.6
If doubt, email me: jary_aka@yahoo
Michael asks…
Find the probability that 85% or more of the sample will be infected, using the normal approximation.?
Here is the question:
In a certain population of mussels, 80% of the individuals are infected with an intestinal parasite. A marine biologist plans to examine 100 randomly chosen mussels from the population. Find the probability that 85% or more of the sampled mussels will be infected, using the normal approximation? Show answer with and without continuity correction.
Thanks for any help you can offer!
MonroyPro answers:
With continuity correction:
P(p > .845) = P[z > (.845 - .8)/sqrt(.8*.2/100)] = P(z > 1.125) = .130295
Without continuity correction:
P(p > .85) = P[z > (.85 - .8)/sqrt(.8*.2/100)] = P(z > 1.25) = .10565
(The actual binomial probability is 0.1285, which shows you that the calculation with the continuity correction is more accurate)
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