Which line contains the pint (6-4) and has a slope of -5/6
1 answer:
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Answer:
(a) Customer will not purchase the light bulbs at significance level of 0.05
(b) Customer will purchase the light bulbs at significance level of 0.01 .
Step-by-step explanation:
We are given that Light bulbs of a certain type are advertised as having an average lifetime of 750 hours. A random sample of 50 bulbs was selected, and the following information obtained:
Average lifetime = 738.44 hours and a standard deviation of lifetimes = 38.2 hours.
Let Null hypothesis, :
= 750 {means that the true average lifetime is same as what is advertised}
Alternate Hypothesis, :
< 750 {means that the true average lifetime is smaller than what is advertised}
Now, the test statistics is given by;
T.S. = ~
where, X bar = sample mean = 738.44 hours
s = sample standard deviation = 38.2 hours
n = sample size = 50
So, test statistics = ~
= -2.14
(a) Now, at 5% significance level, t table gives critical value of -1.6768 at 49 degree of freedom. Since our test statistics is less than the critical value of t, so which means our test statistics will lie in the rejection region and we have sufficient evidence to reject null hypothesis.
Therefore, we conclude that the true average lifetime is smaller than what is advertised and so consumer will not purchase the light bulbs.
(b) Now, at 1% significance level, t table gives critical value of -2.405 at 49 degree of freedom. Since our test statistics is higher than the critical value of t, so which means our test statistics will not lie in the rejection region and we have insufficient evidence to reject null hypothesis.
Therefore, we conclude that the true average lifetime is same as what it has been advertised and so consumer will purchase the light bulbs.
Answer:
Step-by-step explanation:
Given that a popcorn company builds a machine to fill 1 kg bags of popcorn. They test the first hundred bags filled and find that the bags have an average weight of 1,040 grams with a standard deviation of 25 grams.
i.e. Sample mean = 1040 and
Sample std dev s = 25 gm
Sample size n = 100
Hence by central limit theorem we have the sample mean follows a normal distribution with mean =1040 and std dev = s = 25 gm
Normal curve would be with mean 1040 and std deviatin 25
b) P(X>1115)
= 1-0.9987
=0.0013
i.e. 0.13% would receive a bag that had a weight greater than 1115 grams