Answer:
Step-by-step explanation:
From the information given, we would write the hypothesis.
For the null hypothesis,
H0 : µ = 70
For the null hypothesis,
Ha : µ > 70
This is a right tailed test because of the symbol of greater than.
The decision rule is to reject the null hypothesis if the level of significance is greater than the p value and accept the null hypothesis if the level of significance is lesser than the p value.
Therefore, since the significance level, 0.05 > p value, 0.01635, then we would reject the null hypothesis. There is enough evidence that the mean speed of all cars is greater than the posted speed limit of 70 mph.
Given:
μ = 68 in, population mean
σ = 3 in, population standard deviation
Calculate z-scores for the following random variable and determine their probabilities from standard tables.
x = 72 in:
z = (x-μ)/σ = (72-68)/3 = 1.333
P(x) = 0.9088
x = 64 in:
z = (64 -38)/3 = -1.333
P(x) = 0.0912
x = 65 in
z = (65 - 68)/3 = -1
P(x) = 0.1587
x = 71:
z = (71-68)/3 = 1
P(x) = 0.8413
Part (a)
For x > 72 in, obtain
300 - 300*0.9088 = 27.36
Answer: 27
Part (b)
For x ≤ 64 in, obtain
300*0.0912 = 27.36
Answer: 27
Part (c)
For 65 ≤ x ≤ 71, obtain
300*(0.8413 - 0.1587) = 204.78
Answer: 204
Part (d)
For x = 68 in, obtain
z = 0
P(x) = 0.5
The number of students is
300*0.5 = 150
Answer: 150
Answer:
72
Step-by-step explanation:
We are assuming that all girls in the group bought the same number of items.
Therefore, we need to find the highest common factor of 72, 144 and 216.
HCF
72 = 2 * 2 * 2 * 3 * 3
144 = 2 * 2 * 2 * 2 * 3 * 3
216 = 2 * 2 * 2 * 3 * 3 * 3
The product of the emboldened numbers is the highest common factor.
That is:
2 * 2 * 2 * 3 * 3 = 72
Therefore, the largest possible number of girls in the group is 72.
For a set population, does a parameter ever change?
Answer: For a set population, a parameter never change.
Because while computing the parameter each and every unit of the population is studied. Therefore, we can not expect a parameter to vary.
If there are three different samples of the same size from a set population, is it possible to get three different values for the same statistic?
Answer: Data from samples may vary from sample to sample, and so corresponding sample statistic may vary from sample to sample.
Because while calculating the sample statistic, we consider only the part of population. Every time we draw a sample from population, there is every possibility of getting different sample. Therefore, data from samples may vary from sample to sample and corresponding sample statistic may vary from sample to sample.
