If the quality of teaching is similar in a school, the scores on a standardized test will have a standard deviation of 14. the superintendent wants to know if there is a disparity in teaching quality, and decides to investigate whether the standard deviation of test scores has changed. she samples 24 random students and finds a mean score of 156 with a standard deviation of 2.4354. is there evidence that the standard deviation of test scores has decreased at the α=0.01 level? assume the population is normally distributed.

answer: first option i.e. 'a' is correct.

step-by-step explanation:

since we have given that

number of minutes to wrap a small gift box = 4 minutes

we need to find the number of gifts to be wrapped in 5 minutes

since there is a direct variation, as the number of minutes will increase with   number of gifts to be wrapped.

so, let the number of gifts to be wrapped in 5 minutes be x.

so, it becomes,

hence, first option 'a'   is correct.

they would have to work 32 hours.

sina-sinb

cosb+cosa

tana-tanb

cos0+cos x pi/3

20tan

step-by-step explanation:

i think it would be c

mark brainliest if im right

step-by-step explanation: