Astudy was conducted to investigate the relationship between maternal smoking during pregnancy and the presence of congenital malformations in the child. among children who suffer from an abnormality other than down 's syndrome or an oral cleft, 32.8% have mothers who smoked during pregnancy [10] . this proportion is homogeneous for children with various types of defects. a) if you were to select repeated samples of size 25 from this population, what could you say about the distribution of the sample proportions? list 3 properties.

b) among the samples of size 25, what fraction has a sample proportion of .45 or higher?

c) what fraction has a sample proportion of .20 or lower?

d) what value of p cuts off the lower 10% of the distribution?

probability for j is 1/4

while

a is 1/6

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."

answer: 7 x 2/5 = 2.8 hours, is your answer. your welcome! : 3

step-by-step explanation: first work out how long it took to hose 1/7 of the lawn which is 2/5 hours. times that by 7 to get the whole lawn.

sorry i don't know the other answer. i didn't learn what a proportional relationship is.