Is this equation an identity? z = -10 − z
1 answer:
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<u>Answer</u>: No, we do not have sufficient evidence to conclude that the mean call duration, µ, is different from the 2010 mean of 9.4 minutes.
Step-by-step explanation:
As per given , we have
, since
is two-tailed so , the test is a two tail test.
Since population standard deviation is unknown, so we use t-test.
Critical value (two-tailed) for significance level of 0.01=
For n =50 , and s= 4.8
Test statistic :
Since test statistic value (-1.18) lies in critical interval (-2.609228, 2.609228), it means the null hypothesis is failed to reject.
We do not have sufficient evidence to conclude that the mean call duration, µ, is different from the 2010 mean of 9.4 minutes.
Answer:
A) Approximate percentage of women with platelet counts within 2 standard deviations of the mean, or between 118.5 and 377.3 = 95%
B) approximate percentage of women with platelet counts between 53.8 and 442.0 = 99.7%
Step-by-step explanation:
We are given;
mean;μ = 247.9
standard deviation;σ = 64.7
A) We want to find the approximate percentage of women with platelet counts within 2 standard deviations of the mean, or between 118.5 and 377.3.
Now, from the image attached, we can see that from the empirical curve, the probability of 1 standard deviation from the mean is (34% + 34%) = 68 %.
While probability of 2 standard deviations from the mean is (13.5% + 34% + 34% + 13.5%) = 95%
Thus, approximate percentage of women with platelet counts within 2 standard deviations of the mean, or between 118.5 and 377.3 = 95%
B) Now, we want to find the approximate percentage of women with platelet counts between 53.8 and 442.0.
53.8 and 442.0 represents 3 standard deviations from the mean.
Let's confirm that.
Since mean;μ = 247.9
standard deviation;σ = 64.7 ;
μ = 247.9
σ = 64.7
μ + 3σ = 247.9 + 3(64.7) = 442
Also;
μ - 3σ = 247.9 - 3(64.7) = 53.8
Again from the empirical curve attached, we cans that at 3 standard deviations from the mean, we have a percentage probability of;
(2.35% + 13.5% + 34% + 34% + 13.5% + 2.35%) = 99.7%
