Answer:
98% confidence interval is (-0.105 , 0.265)
Step-by-step explanation:
n1 = 75 n2 = 75
X1 = 48 X2 = 42
P1 = X1/N1 = 0.64 P2 = X2/N2 = 0.56
98% confidence interval for difference between two proportions is :
P1 - P2 <u>+</u> Z
= 0.08 <u>+</u> 0.185
= (-0.105 , 0.265)
98% confidence interval is (-0.105 , 0.265)
Answer: c)[50,60]
Step-by-step explanation:
The Empirical rule says that , About 68% of the population lies with the one standard deviation from the mean (For normally distribution).
We are given that , The heights of students in a class are normally distributed with mean 55 inches and standard deviation 5 inches.
Then by Empirical rule, about 68% of the heights of students lies between one standard deviation from mean.
i.e. about 68% of the heights of students lies between
i.e. about 68% of the heights of students lies between
Here,
i.e. The required interval that contains the middle 68% of the heights. = [50,60]
Hence, the correct answer is c) (50,60)