A 95% confidence is given by (15,20) . The interval is based on a sample of size n=25 .
1 answer:
Answer:
b. quadruple the sample size.
Step-by-step explanation:
Given that a 95% confidence is given by (15,20) .
this implies that mean = average of lower and higher bounds of confidence interval =
Margin of error = Upper bound - Mean =
Confidence level = 95%
Critical value = 1.96
Std error =
Std devition = Std error * sqrt n = 6.3775
If we want to reduce margin of error by half we must get margin of error as 1.25
For that std error for same critical value = 0.63775
Std deviation did not change
So sample size only changed which implies that sample size is 4 times the original
b. quadruple the sample size.
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Angle B measures 30 degrees.
Step-by-step explanation:
Step 1:
If two angles are complementary, the sum of the two angles will equal 90°.
So if angles A and B are complementary, the sum of the angles A and B will equal 90°.
It is given that cos A = 0.5, we can determine the value of A by taking the cos inverse of the value 0.5.
Step 2:
If cos A = 0.5, A = So angle A is 60°.
As A and B are complementary, angle A + angle B = 90°.
So 60° + angle B = 90°, angle B = 90° - 60° = 30°.
So angle B measures 30° while angle A measures 60°.