28. baby talk: in a sample of 77 children, the mean age at which they
first began to combine words was 16.51 months, with a standard
deviation of 9.59 months.
a. construct a 95% confidence interval for the mean age at which
children first begin to combine words.
b. if a sample of 50 children had been studied, would you expect
the confidence interval to be wider or narrower than the interval
constructed in part (a)? explain.

answer: #1 ads up by 8 and i don't know #2

answer: two angles are called supplementary if they add up to 180°. example: the two angles (140° and 40°) are supplementary because they add up to 180°.

step-by-step explanation:

answer: i dont know i want points

step-by-step explanation:

step-by-step explanation:

consider the parallelogram shown in the attached image.

in the parallelogram hijk, the length of hk is given as,

from the properties of parallelogram we know that the opposite sides of a parallelogram are parallel to each other and are equal in measure.

therefore, the length of the side ij must be equal to the length of the side hk and that is .

hence, the expression for the length of ij confirms that hijk is a parallelogram.