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: a

step-by-step explanation:

y = i/2 xtnop + (3i/2 tnop+ 1)

step-by-step explanation:

the picture is the step by step explanation.

in 1995, potato plants were taken into space aboard the space shuttle columbia.

step-by-step explanation:

d. $180

step-by-step explanation:

if the dimensions of the room is 9ft by 12 ft, we have the area of the floor as,

so the area of the floor is 108 square feet, converting that into square yards we get,

the cost of carpet is $15 per square yard, therefore the cost of carpet for 12 square yards is,

hence, the cost of carpet is $180.

assuming the dimensions of the room be,

15 ft by 12 ft

so, the area of the floor of that room is,

we can convert 180 square feet into square yards, we know that,

1 sq ft = 0.111 sq yard

so, 180 square feet is,

so the area of floor is 20 square yards.

now, the cost of carpet is 15 dollars per square yard, therefore the cost of carpet for 20 square yards is,

so, it will cost $300.