The mean weight of the students in a school is 70 kilograms. A random sample of 25 students was taken and the mean weight was found to be 55 kilograms with a standard deviation of 20 kilograms. What is the test statistics? Express your answer into 2 decimal places (example: 25.00)

-3.75

Step-by-step explanation:

The question refers to the fact that we calculate the value of z in order to know how successful the random sample is in terms of probabilities:

z = (x -m) / (sd / n ^ (1/2))

where x is the value to evaluate, that is to say 55 kg, the standard deviation is sd and would be 20 kg, m is the mean that is 70 and n the size of the random sample that is 25, replacing we are left with:

z = (55 - 70) / (20/25 ^ (1/2))

z = -3.75

this value represents practically 0%, making the sampling that was made very unlikely

30 miles

step-by-step explanation:

we know that 60 seconds equals 1 minute and 60 minutes 1 hour

44 ft       60 sec     60 min     158400   ft

  *   *   =

1 sec       1 min       1 hour         hour

we know that there are 5280 ft per mile

158400   ft       1 mile         30 miles

  *   =

1   hour               5280 ft     1 hour

so in 1 hour   it can travel 30 miles

solution:

we have to construct

∠m nt ≅ ∠p qr

the steps to draw this construction are

step 1: use a compass to draw an arc from point q which intersects the side pq at point a and the side qr at point b.

step 2: draw a segment nt and use the same width of the compass to draw an arc from point n which intersects the segment nt at a point x.

step 3:

step 4: join points n and y using a straightedge.

step 3:

option (d).maintaining the same width of the compass as ab, draw an arc from point x such that it intersects the arc drawn from n in a point y.

to draw   congruent angles , 1. width of compasses while drawing two angles should be same i.e from point at which angle has to be drawn, 2.the distance between the two points where the compass intersects the two sides should be same while drawing any two congruent angles.