Cos x=1/4, find cos2x if x is in the first quadrant

Pls answer ASAP

Say that a supplier claims they are 99% confident that their products will be in the interval of 50.02 to 50.38. you take samples and find that the 99% confidence interval of what they are sending is 50.00 to 50.36. what conclusion can be made? homework : 5vd. comparing sample confidence intervals with given intervals (links to an external site.)links to an external site. (3: 43) 5dc. confidence intervals in manufacturing, high vs low level of confidence, wide vs narrow (links to an external site.)links to an external site. (docx) the supplier is less accurate than they claimed the supplier products have a lower mean than claimed the supplier is more accurate than they claimed the supplier products have a higher mean than claimed