Answer:
Step-by-step explanation:
Let X be the SRS scores of students.
Given that X is normal with standard deviation about 6.5.
Mean difference = is desired
i.e. Z score should be
Std error = std deviation of sample = 0.447
b)
So std error must be 0.997 and sample size must be atleast 193 to get the difference of x bar and mu to lie within 1.3 points in either direction
Answer:
the Pythagorean theorem states: a^2 + b^2 = c^2
1) in this case a=18 and b1=25
18^2 + 25^2 = c1^2
324 + 625 = c1^2
949 = c1^2
√949 = c1
cca. 30.8 = c1
2) in this case a=18 and b' = b2 - b1 = 40 - 25 = 15
in the picture im attaching i highlighted the triangles we are working with, and there you can clearly see that b' (the horizontal line at the bottom of the red tr.) is the difference between the lines b2 and b1
now you can use the same technique as in the first case, and the final answer will be cca. 23.4 = c2
3) in this case a=18 and b'' = b4 - b3 = 75 - 55 = 20
same thing as number 2, final answer cca. 26.9 = c3
