Answer:
138 miles
Step-by-step explanation:
23x6=138
Pls give brainliest
Answer:
C
Step-by-step explanation:
Its C because its x (a variable) and is costanly changing
Answer:
a)
90% confidence interval for the mean grading time of all composition papers.
(12.47981 , 13.52019)
b)
Appropriate inequality
The interval is ( 12.47981 < μ < 13.52019)
Step-by-step explanation:
<u><em>Explanation</em></u>:-
a)
Given sample size 'n' = 40
Mean of the sample = 13 minutes
standard deviation = 2 min
level of significance = 0.10 or 90%
90% confidence interval for the mean grading time of all composition papers.
![( x^{-} - Z_{0.1} \frac{S.D}{\sqrt{n} } , x^{-} + Z_{0.10} \frac{S.D}{\sqrt{n} } )](https://tex.z-dn.net/?f=%28%20x%5E%7B-%7D%20-%20Z_%7B0.1%7D%20%5Cfrac%7BS.D%7D%7B%5Csqrt%7Bn%7D%20%7D%20%2C%20x%5E%7B-%7D%20%2B%20Z_%7B0.10%7D%20%5Cfrac%7BS.D%7D%7B%5Csqrt%7Bn%7D%20%7D%20%29)
![( 13 - 1.645 \frac{2}{\sqrt{40} } , 13 +1.645 \frac{2}{\sqrt{40} } )](https://tex.z-dn.net/?f=%28%2013%20-%201.645%20%5Cfrac%7B2%7D%7B%5Csqrt%7B40%7D%20%7D%20%2C%2013%20%2B1.645%20%5Cfrac%7B2%7D%7B%5Csqrt%7B40%7D%20%7D%20%29)
( 13 - 0.52019 , 13 + 0.52019)
(12.47981 , 13.52019)
b)
The interval is ( 12.47981 < μ < 13.52019)
∵ ΔSRQ is a right triangle
and RT⊥SQ
∴ x² = ST * TQ
∴ x² = 9 *16 = 144
∴ x = √144 = 12